Nanotechnology has shown interest in the utilization of agricultural byproducts as a source for nanostructured materials. Due to their distinctive chemical, thermal, mechanical, morphological, optical, and electrical ...Nanotechnology has shown interest in the utilization of agricultural byproducts as a source for nanostructured materials. Due to their distinctive chemical, thermal, mechanical, morphological, optical, and electrical properties, cellulose nanocrystals (CNCs) have often found utility in a variety of fields. Using sulphuric acid with a 64% weight-to-weight ratio, we managed to extract CNCs chemically from rice husks for the study and examined the effects of varying the hydrolysis period and synthesized composites on optical and thermal characteristics. The usual procedure for preparation was followed, but set the hydrolysis time for 40, 60 and 90 minutes, and also varied temperature at 40˚C, 45˚C and 50˚C. Tonic water and silver nanoparticles were used to synthesize the composites at different ratios. The samples were characterized using UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. From the results of this study, maximum absorption is observed to shift to shorter wavelengths with an increase in temperature, and the peak absorbance (maximum wavelength) generally increased with hydrolysis time at all three temperatures. The FTIR spectrum of cellulose nanocrystals (CNCs), AgNPs and their composites exhibited distinctive absorption bands indicative of their molecular structure and chemical composition. From the TGA findings, the two composites had a relatively low thermal stability, hence restricting their application to a fixed temperature and below. Additionally, this property makes the composite easily formable into intricate designs, which is ideal for use in optical components and sensors. The low melting point also facilitates recycling and reprocessing, enhancing sustainability by enabling the reuse of the material in various applications. Moreover, the composite’s sensitivity to temperature can be useful in temperature-sensing applications, where changes in its properties at lower temperatures can provide valuable optical feedback.展开更多
Water contamination in areas of formal and informal polymetallic mining is a growing concern in the Peruvian highlands. At the same time, there are agricultural activities that use contaminated water from these rivers...Water contamination in areas of formal and informal polymetallic mining is a growing concern in the Peruvian highlands. At the same time, there are agricultural activities that use contaminated water from these rivers for irrigation. This could contaminate the agricultural products grown on these lands, such as potatoes. It is, therefore, necessary and a priority to determine the adsorption characteristics of these derivatives and to be able to use these natural adsorbents to decontaminate water contaminated with heavy metals.展开更多
Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intend...Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intends to study the photocatalytic production of hydrogen from D-(+)-Glucose by using different groups of catalysts that have been prepared (M2+ = Zn, Mg and Ni) M2+/Ti4+ Al3+-LDHs (layered double hydroxides). It is then loaded Pd on the catalyst, and the effect of the composite catalyst, layered double hydroxides, is measured. After calcining, the catalyst for the conversion of Layered Double Hydroxides (LDHs) to Layered Double Oxides (LDOs) is used to produce hydrogen gas from glucose. Photocatalytic reforming of glucose-derived compounds is an efficient method for the production of hydrogen. The purpose is to study the effect of metal ions on layered double oxide (LDO) materials by loading Pd and investigate hydrogen production from glucose. The metal cations in the layer were distributed through the preparation of the catalyst process by ion and atom scale between the layers, which were dispersed systematically, as well as the controlled component catalysis. This process shows that ZnTiAl-LDO had the best effect as a catalyst in producing hydrogen compared to NiTiAl-LDO and MgTiAl-LDO.展开更多
In the emerging world of biotech innovation, the fast-to-clinic/market strategy has emerged as a critical “mantra” for biotech, investors, and CDMOs. This approach addresses the escalating costs and complexities of ...In the emerging world of biotech innovation, the fast-to-clinic/market strategy has emerged as a critical “mantra” for biotech, investors, and CDMOs. This approach addresses the escalating costs and complexities of research and development by streamlining the path from concept to clinical trials and, ultimately, to market. The article delves into the intricacies of implementing a fast-to-clinic/market strategy, underlining the empowering role of strategic decision-making in preclinical and commercial stages. The plan advocates for a phase-appropriate approach, where the development decision is tailored to each phase of the product’s lifecycle. This ensures that resources are allocated efficiently, risks are managed effectively, and the product can move through the development pipeline accelerated without compromising quality or regulatory compliance. The article also discusses the role of CDMOs in facilitating rapid product development and the essential factors biotech companies must consider when selecting a partner for outsourcing. These factors include the CDMO’s expertise in navigating regulatory landscapes, technological capabilities, and ability to scale processes efficiently. Moreover, the article stresses the importance of agility and flexibility in the fast-to-clinic/market approach. Biotech companies are encouraged to adopt adaptable strategies that respond to the fast-evolving regulatory and market landscapes.展开更多
Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic t...Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic table. The lithium atom has a strong tendency to release one electron and constitute a positive charge, as Li<sup> </sup>. Initially, lithium metal was employed as a negative electrode, which released electrons. However, it was observed that its structure changed after the repetition of charge-discharge cycles. To remedy this, the cathode mainly consisted of layer metal oxide and olive, e.g., cobalt oxide, LiFePO<sub>4</sub>, etc., along with some contents of lithium, while the anode was assembled by graphite and silicon, etc. Moreover, the electrolyte was prepared using the lithium salt in a suitable solvent to attain a greater concentration of lithium ions. Owing to the lithium ions’ role, the battery’s name was mentioned as a lithium-ion battery. Herein, the presented work describes the working and operational mechanism of the lithium-ion battery. Further, the lithium-ion batteries’ general view and future prospects have also been elaborated.展开更多
The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the...The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the extrusion technique. Two popular procedures that vary in the kind of dye used and the final product’s texture are cast film and blown film. In the horizontal extrusion moulding method known as “cast film”, heated resin is injected into a flat dye and allowed to cool on chill rolls. The film produced is clear, lightweight, and appropriate for lamination;its thickness varies based on the winding speed and the film is slower to crystallize and has less clarity but more durability because the resin molecules have reoriented, facing limitation of high wastage generation. This study primarily focused on the preparation of polybag film using the blown film extrusion process, utilizing high-quality polymer resins such as polyester polyethylene (PP) and linear low-density polyethylene (LLDPE) to minimize waste generation. The novelty of the process was reflected in minimising the waste generation. The control parameters considered in this study are temperature, pressure, and air intake volume. We investigated the influence of these critical process control parameters on the gauge thickness, optical properties, and mechanical strength of the polybag film produced through blown film extrusion. Additionally, we replicated the blown film process using simulation software developed at Pennsylvania College of Technology. The simulation results confirmed the overall stability of the polybag film produced through the blown film extrusion process.展开更多
The performance of a newly designed tri-lobe industrial lobe pump of high capacity is simulated by using commercial CFD solver Ansys Fluent. A combination of user-defined-functions and meshing strategies is employed t...The performance of a newly designed tri-lobe industrial lobe pump of high capacity is simulated by using commercial CFD solver Ansys Fluent. A combination of user-defined-functions and meshing strategies is employed to capture the rotation of the lobes. The numerical model is validated by comparing the simulated results with the literature values. The processes of suction, displacement, compression and exhaust are accurately captured in the transient simulation. The fluid pressure value remains in the range of inlet pressure value till the processes of suction and displacement are over. The instantaneous process of compression is accurately captured in the simulation. The movement of a particular working chamber is traced along the gradual degree of lobe’s rotation. At five different degrees of lobe’s rotation, pressure contour plots are reported which clearly shows the pressure values inside the working chamber. Each pressure value inside the working chamber conforms to the particular process in which the working chamber is operating. Finally, the power requirement at the shaft of rotation is estimated from the simulated values. The estimated value of power requirement is 3.61 BHP FHP whereas the same calculated theoretically is 3 BHP FHP. The discrepancy is attributed to the assumption of symmetry of blower along the thickness.展开更多
Currently a technique widely used for gold extraction is mercury by amalgamation technique, the tailing produced pollutes water of all kinds, so it is necessary to develop a form of selective mitigation, for which it ...Currently a technique widely used for gold extraction is mercury by amalgamation technique, the tailing produced pollutes water of all kinds, so it is necessary to develop a form of selective mitigation, for which it is necessary to use complexing agents based on calixarene functionalized with mercury sequestering agents. These are immobilized by adding supports based on natural silica to form polymers and make them insoluble in all types of solvents, so that they can be used as an extractor and at the same time regenerate to their original properties for continuous reuse.展开更多
In the present study, energetic and entropic changes are investigated on a comparative basis, as they occur in the volume changes of an ideal gas in the Carnot cycle and in the course of the chemical reaction in a lea...In the present study, energetic and entropic changes are investigated on a comparative basis, as they occur in the volume changes of an ideal gas in the Carnot cycle and in the course of the chemical reaction in a lead-acid battery. Differences between reversible and irreversible processes have been worked out, in particular between reversibly exchanged entropy (∆<sub>e</sub>S) and irreversibly produced entropy (∆<sub>i</sub>S). In the partially irreversible case, ∆<sub>e</sub>S and ∆<sub>i</sub>S add up to the sum ∆S for the volume changes of a gas, and only this function has an exact differential. In a chemical reaction, however, ∆<sub>e</sub>S is independent on reversibility. It arises from the different intramolecular energy contents between products and reactants. Entropy production in a partially irreversible Carnot cycle is brought about through work-free expansions, whereas in the irreversible battery reaction entropy is produced via activated complexes, whereby a certain, variable fraction of the available chemical energy becomes transformed into electrical energy and the remaining fraction dissipated into heat. The irreversible reaction process via activated complexes has been explained phenomenologically. For a sufficiently high power output of coupled reactions, it is essential that the input energy is not completely reversibly transformed, but rather partially dissipated, because this can increase the process velocity and consequently its power output. A reduction of the counter potential is necessary for this purpose. This is not only important for man-made machines, but also for the viability of cells.展开更多
Water is the most abundant liquid on the surface of the earth. It is a liquid whose properties are quite surprising, both as a pure liquid and as a solvent. Water is a very cohesive liquid: its melting and vaporizatio...Water is the most abundant liquid on the surface of the earth. It is a liquid whose properties are quite surprising, both as a pure liquid and as a solvent. Water is a very cohesive liquid: its melting and vaporization temperatures are very high for a liquid that is neither ionic nor metallic, and whose molar mass is low. Thus, water remains liquid at atmospheric pressure up to 100C while similar molecules such as H2S, H2Se, H2Te for example would give a vaporization temperature close to 80C. This cohesion is in fact ensured by hydrogen bonds between water molecules. This type of bonds between neighboring molecules, hydrogen bonds, is quite often found in chemistry [1] [2]. Any change in the state of aggregation of a substance occurs with the absorption or release of a certain amount of latent heat of transformation. Latent heat of fusion, vaporization or sublimation is the ratio of the energy supplied as heat to the mass of the substance that is melted, vaporized or sublimated. As a result of the reversibility of the processes, the fusion heat is equal to the heat released in the reverse process: crystallization and solidification heat. And likewise the heat of vaporization is equal to the heat of condensation. This equality of heat is often used to determine experimentally either of these quantities. There are two main measurement methods: 1) Direct measurement using the calorimeter, 2) Indirect measure based on the use of the VantHoff relationship. The objective of this work is to measure the latent heat of water vaporization and verify the compatibility of the experimental values with the values given by the tables using the indirect method.展开更多
The liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) using fuming sulfuric acid as a catalyst is a traditional method for preparing ε-caprolactam (CPL). This process has drawbacks, such as environment...The liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) using fuming sulfuric acid as a catalyst is a traditional method for preparing ε-caprolactam (CPL). This process has drawbacks, such as environmental pollution, corrosion of equipment, and low added value of by-product ammonium sulfate. This article designed and prepared a green silica gel-supported trifluoromethanesulfonic acid catalyst for the liquid-phase Beckmann rearrangement of CHO to prepare (CPL). The influencing factors of catalyst preparation and the optimal reaction conditions for Beckmann rearrangement were investigated. It was found that the optimal conditions for catalyst preparation were as follows: raw material silica gel:trifluoromethanesulfonic acid = 1:0.2 (mass ratio), room temperature, stirring time of 2.5 hours, and solvent of acetonitrile, silica gel mesh size is 100 - 200. The optimal reaction conditions for Beckmann rearrangement are CHO: catalyst = 1:2 (mass ratio), temperature of 130˚C, solvent of benzonitrile, volume of 30 mL/g CHO, and reaction time of 4 hours. Under the above conditions, the conversion of CHO is 90%, and the selectivity of CPL is 90%.展开更多
In global industrialization, efforts have been made to increase the rate of heat transfer in heat exchanger, minimizing the size of heat exchanger to reduce cost as well as increasing the effectiveness. Helical coil h...In global industrialization, efforts have been made to increase the rate of heat transfer in heat exchanger, minimizing the size of heat exchanger to reduce cost as well as increasing the effectiveness. Helical coil heat exchanger (HCHE) has been proven to be effective in improving heat transfer due to its large surface area. In this study, HCHE was designed to provide hot air needed for fluidized bed drying processes. The HCHE design model was fabricated and evaluated to study the efficiency of the hot air output for a laboratory fluidized bed dryer. The mathematical model for estimation of the final (output) temperature of air, Taf, passing through the HCHE was developed and validated experimentally. The drying of bitter kola particulates was carried out with a drying temperature of 50C 3C and a bed height-to-bed diameter ratio (H/D) of 1.5. The time taken to dry bitter kola particulates to 0.4% moisture content was 1 hour 45 minutes. Hence, HCHE is recommended for use in the production of hot for laboratory-scale fluidized bed dryers.展开更多
The aim of this work is to detect electrogenerated hydroxyl radicals and chlorine by simple and less expensive methods. Preparative electrolyses of perchloric acid (HClO4) and sodium chloride (NaCl) were performed on ...The aim of this work is to detect electrogenerated hydroxyl radicals and chlorine by simple and less expensive methods. Preparative electrolyses of perchloric acid (HClO4) and sodium chloride (NaCl) were performed on a boron-doped diamond (BDD) electrode. The hydroxyl radicals were quantified indirectly by assaying the samples from the HClO4 (0.1 M) electrolysis with a 10−4 M potassium permanganate solution. The investigations showed that the amount of hydroxyl radicals depends on the concentration of HClO4 and the current density. As for chlorine, a qualitative determination was carried out. A mixture of the electrolyte solution of HClO4 (0.1 M) + NaI (0.2 M) + 2 mL of hexane, taken in this order, leads to a purplish-pink coloration attesting to the presence of Cl2. The same test was carried out with NaBr and NaI giving pale and very pale pink colourations, respectively, showing that the intensity of the colouration depends on the strength of the oxidant present. In addition, oxidants were detected during the electrooxidation of metronidazole (MNZ). The results showed the participation of electrogenerated hydroxyl radicals. The generation of chlorine has also been proven. Furthermore, the degradation leads to a chemical oxygen demand (COD) removal rate of 83.48% and the process is diffusion-controlled.展开更多
In this study, a homogeneous alkaline catalyst was used in the production of biodiesel from raw and refined castor oil feedstock. The effect of potassium hydroxide (KOH) as a catalyst between the two feedstocks, raw a...In this study, a homogeneous alkaline catalyst was used in the production of biodiesel from raw and refined castor oil feedstock. The effect of potassium hydroxide (KOH) as a catalyst between the two feedstocks, raw and refined castor oil was compared. The transesterification technique was utilized in this study, aiming to investigate the effect of different parameters, which include the reaction temperature, methanol-to-oil mole ratio, and catalyst concentration at a constant period of 90 minutes. The result revealed the performance of the KOH catalyst on raw castor oil yielded 98.49% FAME, which was higher than the refined castor oil which yielded 97.9% FAME. The optimal conditions obtained from refined castor oil were applied to raw castor oil because of the same properties. The fuel quality of castor oil and produced biodiesel were tested for physicochemical properties.展开更多
With the full growth of energy needs in the world, several studies are now focused on finding renewable sources. The aim of this work is to optimise biofuel formulation from a mixture design by studying physical prope...With the full growth of energy needs in the world, several studies are now focused on finding renewable sources. The aim of this work is to optimise biofuel formulation from a mixture design by studying physical properties, such as specific gravity and kinematic viscosity of various formulated mixtures. Optimization from the mixture plan revealed that in the chosen experimental domain, the optimal conditions are: 40% for used frying oil (UFO), 50% for bioethanol and 10% for diesel. These experimental conditions lead to a biofuel with a density of 0.84 and a kinematic viscosity of 2.97 cSt. These parameters are compliant with the diesel quality certificate in tropical areas. These density and viscosity values were determined according to respective desirability values of 0.68 and 0.75.展开更多
Organic molecules that exhibit long persistent luminescence (LPL) are rapidly gaining attention for a variety of applications. In this study, organic molecules with simple structures were selected and organic long per...Organic molecules that exhibit long persistent luminescence (LPL) are rapidly gaining attention for a variety of applications. In this study, organic molecules with simple structures were selected and organic long persistent luminescence (OLPL) crystals were prepared. The crystal structure of the prepared OLPL crystal was elucidated and the guideline for the design of OLPL crystal was clarified. LPL was observed in OLPL crystals prepared with TMB as the guest molecule and 1,2-bis(diphenylphosphino)ethane as the host molecule. XRD measurements of the OLPL crystals suggest that the guest molecule is a solid solution substituted in the stable crystal structure of the host molecule in a lattice-shrinking direction.展开更多
Coating slurries for making anodes and cathodes of lithium batteries contain a large percentage of solid particles of different chemicals, sizes and shapes in highly viscous media. A thorough mixing of these slurries ...Coating slurries for making anodes and cathodes of lithium batteries contain a large percentage of solid particles of different chemicals, sizes and shapes in highly viscous media. A thorough mixing of these slurries poses a major challenge in the battery manufacturing process. Several types of mixing devices and mixing methods were examined. The conventional turbine stirrers or ball mill mixers could be adequately used for the preparation of anode slurries, but not suitable for cathode slurries. In this study, a newly three-dimensional mixer, in conjunction with a multi-stage mixing sequence was proposed. The mixing effectiveness was examined by means of rheological measurements and flow visualization techniques. Preliminary electrical performance results indicated that the battery obtained using the 3D mixing device with a multi-stage mixing sequence was more efficient to those obtained from conventional methods.展开更多
Electrochemical impedance spectroscopy (EIS) in the l00 kHz-10 mHz frequency range was employed as the main electrochemical technique to study the corrosion protection behaviour of zinc rich epoxy paint in 3% NaCl sol...Electrochemical impedance spectroscopy (EIS) in the l00 kHz-10 mHz frequency range was employed as the main electrochemical technique to study the corrosion protection behaviour of zinc rich epoxy paint in 3% NaCl solution. The EIS results obtained at the open-circuit corrosion potential have been interpreted using a model involving the impedance of particle to particle contact to account for the increasing resistance between zinc particles with immersion period, in addition to the impedance due to the zinc surface oxide layer and the electrical resistivity of the binder. Galvanic current and dc potential measurements allowed us to conclude that the cathodic protection effect of the paint takes some time to be achieved. The loss of cathodic protection is due to a double effect: the decrease of the Zn/Fe area ratio due to Zn corrosion and the loss of electric contact between Zn to Zn particles. Even when the cathodic protection effect by Zn dust become weak, the substrate steel is still protected against corrosion due to the barrier nature of the ZRP film reinforced by Zn.展开更多
In this paper we demonstrate that the residual stress introduced by several different surface finishes affects the critical current density for passivation and the passive current density in the anodic polarization cu...In this paper we demonstrate that the residual stress introduced by several different surface finishes affects the critical current density for passivation and the passive current density in the anodic polarization curve of austenitic stainless steel and that those critical current densities can be reduced by controlling the residual stress by applying a cavitating jet to the backs of specimens. The results show that the current density either increased or decreased depending on the surface finish, and that was decreased by introducing compressive residual stress for all surface finishes.展开更多
In manufacturing process, it is necessary to measure change in CSD (Crystal Size Distribution) with time accurately because CSD is one of the most important indices that evaluate quality of products. FBRM (Focused Bea...In manufacturing process, it is necessary to measure change in CSD (Crystal Size Distribution) with time accurately because CSD is one of the most important indices that evaluate quality of products. FBRM (Focused Beam Reflectance Measurement) can measure CLD (Chord Length Distribution) in line, but CLD is different from CSD because of principle of FBRM. However, if CSD is determined beforehand, CLD can be calculated from the CSD with statistical method. First, when crystal shape is defined from the characteristic crystal size, the matrix of each crystal shape which transforms CSD into CLD in a uniform manner is calculated with Monte Carlo analysis. Characteristic crystal size is added to the variables defining chord length in order to avoid complex integrals and apply the change in crystal shape with characteristic crystal size to the transforming matrix. Secondly, CSD and CLD are actually measured in suspension of acetaminophen in ethanol and suspension of L-arginine in water to demonstrate the validity of 2 matrices. Lastly, these matrices are multiplied by some simple CSD models to test the properties of these matrices and demonstrate the utility of this transformation.展开更多
文摘Nanotechnology has shown interest in the utilization of agricultural byproducts as a source for nanostructured materials. Due to their distinctive chemical, thermal, mechanical, morphological, optical, and electrical properties, cellulose nanocrystals (CNCs) have often found utility in a variety of fields. Using sulphuric acid with a 64% weight-to-weight ratio, we managed to extract CNCs chemically from rice husks for the study and examined the effects of varying the hydrolysis period and synthesized composites on optical and thermal characteristics. The usual procedure for preparation was followed, but set the hydrolysis time for 40, 60 and 90 minutes, and also varied temperature at 40˚C, 45˚C and 50˚C. Tonic water and silver nanoparticles were used to synthesize the composites at different ratios. The samples were characterized using UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. From the results of this study, maximum absorption is observed to shift to shorter wavelengths with an increase in temperature, and the peak absorbance (maximum wavelength) generally increased with hydrolysis time at all three temperatures. The FTIR spectrum of cellulose nanocrystals (CNCs), AgNPs and their composites exhibited distinctive absorption bands indicative of their molecular structure and chemical composition. From the TGA findings, the two composites had a relatively low thermal stability, hence restricting their application to a fixed temperature and below. Additionally, this property makes the composite easily formable into intricate designs, which is ideal for use in optical components and sensors. The low melting point also facilitates recycling and reprocessing, enhancing sustainability by enabling the reuse of the material in various applications. Moreover, the composite’s sensitivity to temperature can be useful in temperature-sensing applications, where changes in its properties at lower temperatures can provide valuable optical feedback.
文摘Water contamination in areas of formal and informal polymetallic mining is a growing concern in the Peruvian highlands. At the same time, there are agricultural activities that use contaminated water from these rivers for irrigation. This could contaminate the agricultural products grown on these lands, such as potatoes. It is, therefore, necessary and a priority to determine the adsorption characteristics of these derivatives and to be able to use these natural adsorbents to decontaminate water contaminated with heavy metals.
文摘Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intends to study the photocatalytic production of hydrogen from D-(+)-Glucose by using different groups of catalysts that have been prepared (M2+ = Zn, Mg and Ni) M2+/Ti4+ Al3+-LDHs (layered double hydroxides). It is then loaded Pd on the catalyst, and the effect of the composite catalyst, layered double hydroxides, is measured. After calcining, the catalyst for the conversion of Layered Double Hydroxides (LDHs) to Layered Double Oxides (LDOs) is used to produce hydrogen gas from glucose. Photocatalytic reforming of glucose-derived compounds is an efficient method for the production of hydrogen. The purpose is to study the effect of metal ions on layered double oxide (LDO) materials by loading Pd and investigate hydrogen production from glucose. The metal cations in the layer were distributed through the preparation of the catalyst process by ion and atom scale between the layers, which were dispersed systematically, as well as the controlled component catalysis. This process shows that ZnTiAl-LDO had the best effect as a catalyst in producing hydrogen compared to NiTiAl-LDO and MgTiAl-LDO.
文摘In the emerging world of biotech innovation, the fast-to-clinic/market strategy has emerged as a critical “mantra” for biotech, investors, and CDMOs. This approach addresses the escalating costs and complexities of research and development by streamlining the path from concept to clinical trials and, ultimately, to market. The article delves into the intricacies of implementing a fast-to-clinic/market strategy, underlining the empowering role of strategic decision-making in preclinical and commercial stages. The plan advocates for a phase-appropriate approach, where the development decision is tailored to each phase of the product’s lifecycle. This ensures that resources are allocated efficiently, risks are managed effectively, and the product can move through the development pipeline accelerated without compromising quality or regulatory compliance. The article also discusses the role of CDMOs in facilitating rapid product development and the essential factors biotech companies must consider when selecting a partner for outsourcing. These factors include the CDMO’s expertise in navigating regulatory landscapes, technological capabilities, and ability to scale processes efficiently. Moreover, the article stresses the importance of agility and flexibility in the fast-to-clinic/market approach. Biotech companies are encouraged to adopt adaptable strategies that respond to the fast-evolving regulatory and market landscapes.
文摘Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic table. The lithium atom has a strong tendency to release one electron and constitute a positive charge, as Li<sup> </sup>. Initially, lithium metal was employed as a negative electrode, which released electrons. However, it was observed that its structure changed after the repetition of charge-discharge cycles. To remedy this, the cathode mainly consisted of layer metal oxide and olive, e.g., cobalt oxide, LiFePO<sub>4</sub>, etc., along with some contents of lithium, while the anode was assembled by graphite and silicon, etc. Moreover, the electrolyte was prepared using the lithium salt in a suitable solvent to attain a greater concentration of lithium ions. Owing to the lithium ions’ role, the battery’s name was mentioned as a lithium-ion battery. Herein, the presented work describes the working and operational mechanism of the lithium-ion battery. Further, the lithium-ion batteries’ general view and future prospects have also been elaborated.
文摘The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the extrusion technique. Two popular procedures that vary in the kind of dye used and the final product’s texture are cast film and blown film. In the horizontal extrusion moulding method known as “cast film”, heated resin is injected into a flat dye and allowed to cool on chill rolls. The film produced is clear, lightweight, and appropriate for lamination;its thickness varies based on the winding speed and the film is slower to crystallize and has less clarity but more durability because the resin molecules have reoriented, facing limitation of high wastage generation. This study primarily focused on the preparation of polybag film using the blown film extrusion process, utilizing high-quality polymer resins such as polyester polyethylene (PP) and linear low-density polyethylene (LLDPE) to minimize waste generation. The novelty of the process was reflected in minimising the waste generation. The control parameters considered in this study are temperature, pressure, and air intake volume. We investigated the influence of these critical process control parameters on the gauge thickness, optical properties, and mechanical strength of the polybag film produced through blown film extrusion. Additionally, we replicated the blown film process using simulation software developed at Pennsylvania College of Technology. The simulation results confirmed the overall stability of the polybag film produced through the blown film extrusion process.
文摘The performance of a newly designed tri-lobe industrial lobe pump of high capacity is simulated by using commercial CFD solver Ansys Fluent. A combination of user-defined-functions and meshing strategies is employed to capture the rotation of the lobes. The numerical model is validated by comparing the simulated results with the literature values. The processes of suction, displacement, compression and exhaust are accurately captured in the transient simulation. The fluid pressure value remains in the range of inlet pressure value till the processes of suction and displacement are over. The instantaneous process of compression is accurately captured in the simulation. The movement of a particular working chamber is traced along the gradual degree of lobe’s rotation. At five different degrees of lobe’s rotation, pressure contour plots are reported which clearly shows the pressure values inside the working chamber. Each pressure value inside the working chamber conforms to the particular process in which the working chamber is operating. Finally, the power requirement at the shaft of rotation is estimated from the simulated values. The estimated value of power requirement is 3.61 BHP FHP whereas the same calculated theoretically is 3 BHP FHP. The discrepancy is attributed to the assumption of symmetry of blower along the thickness.
文摘Currently a technique widely used for gold extraction is mercury by amalgamation technique, the tailing produced pollutes water of all kinds, so it is necessary to develop a form of selective mitigation, for which it is necessary to use complexing agents based on calixarene functionalized with mercury sequestering agents. These are immobilized by adding supports based on natural silica to form polymers and make them insoluble in all types of solvents, so that they can be used as an extractor and at the same time regenerate to their original properties for continuous reuse.
文摘In the present study, energetic and entropic changes are investigated on a comparative basis, as they occur in the volume changes of an ideal gas in the Carnot cycle and in the course of the chemical reaction in a lead-acid battery. Differences between reversible and irreversible processes have been worked out, in particular between reversibly exchanged entropy (∆<sub>e</sub>S) and irreversibly produced entropy (∆<sub>i</sub>S). In the partially irreversible case, ∆<sub>e</sub>S and ∆<sub>i</sub>S add up to the sum ∆S for the volume changes of a gas, and only this function has an exact differential. In a chemical reaction, however, ∆<sub>e</sub>S is independent on reversibility. It arises from the different intramolecular energy contents between products and reactants. Entropy production in a partially irreversible Carnot cycle is brought about through work-free expansions, whereas in the irreversible battery reaction entropy is produced via activated complexes, whereby a certain, variable fraction of the available chemical energy becomes transformed into electrical energy and the remaining fraction dissipated into heat. The irreversible reaction process via activated complexes has been explained phenomenologically. For a sufficiently high power output of coupled reactions, it is essential that the input energy is not completely reversibly transformed, but rather partially dissipated, because this can increase the process velocity and consequently its power output. A reduction of the counter potential is necessary for this purpose. This is not only important for man-made machines, but also for the viability of cells.
文摘Water is the most abundant liquid on the surface of the earth. It is a liquid whose properties are quite surprising, both as a pure liquid and as a solvent. Water is a very cohesive liquid: its melting and vaporization temperatures are very high for a liquid that is neither ionic nor metallic, and whose molar mass is low. Thus, water remains liquid at atmospheric pressure up to 100C while similar molecules such as H2S, H2Se, H2Te for example would give a vaporization temperature close to 80C. This cohesion is in fact ensured by hydrogen bonds between water molecules. This type of bonds between neighboring molecules, hydrogen bonds, is quite often found in chemistry [1] [2]. Any change in the state of aggregation of a substance occurs with the absorption or release of a certain amount of latent heat of transformation. Latent heat of fusion, vaporization or sublimation is the ratio of the energy supplied as heat to the mass of the substance that is melted, vaporized or sublimated. As a result of the reversibility of the processes, the fusion heat is equal to the heat released in the reverse process: crystallization and solidification heat. And likewise the heat of vaporization is equal to the heat of condensation. This equality of heat is often used to determine experimentally either of these quantities. There are two main measurement methods: 1) Direct measurement using the calorimeter, 2) Indirect measure based on the use of the VantHoff relationship. The objective of this work is to measure the latent heat of water vaporization and verify the compatibility of the experimental values with the values given by the tables using the indirect method.
文摘The liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) using fuming sulfuric acid as a catalyst is a traditional method for preparing ε-caprolactam (CPL). This process has drawbacks, such as environmental pollution, corrosion of equipment, and low added value of by-product ammonium sulfate. This article designed and prepared a green silica gel-supported trifluoromethanesulfonic acid catalyst for the liquid-phase Beckmann rearrangement of CHO to prepare (CPL). The influencing factors of catalyst preparation and the optimal reaction conditions for Beckmann rearrangement were investigated. It was found that the optimal conditions for catalyst preparation were as follows: raw material silica gel:trifluoromethanesulfonic acid = 1:0.2 (mass ratio), room temperature, stirring time of 2.5 hours, and solvent of acetonitrile, silica gel mesh size is 100 - 200. The optimal reaction conditions for Beckmann rearrangement are CHO: catalyst = 1:2 (mass ratio), temperature of 130˚C, solvent of benzonitrile, volume of 30 mL/g CHO, and reaction time of 4 hours. Under the above conditions, the conversion of CHO is 90%, and the selectivity of CPL is 90%.
文摘In global industrialization, efforts have been made to increase the rate of heat transfer in heat exchanger, minimizing the size of heat exchanger to reduce cost as well as increasing the effectiveness. Helical coil heat exchanger (HCHE) has been proven to be effective in improving heat transfer due to its large surface area. In this study, HCHE was designed to provide hot air needed for fluidized bed drying processes. The HCHE design model was fabricated and evaluated to study the efficiency of the hot air output for a laboratory fluidized bed dryer. The mathematical model for estimation of the final (output) temperature of air, Taf, passing through the HCHE was developed and validated experimentally. The drying of bitter kola particulates was carried out with a drying temperature of 50C 3C and a bed height-to-bed diameter ratio (H/D) of 1.5. The time taken to dry bitter kola particulates to 0.4% moisture content was 1 hour 45 minutes. Hence, HCHE is recommended for use in the production of hot for laboratory-scale fluidized bed dryers.
文摘The aim of this work is to detect electrogenerated hydroxyl radicals and chlorine by simple and less expensive methods. Preparative electrolyses of perchloric acid (HClO4) and sodium chloride (NaCl) were performed on a boron-doped diamond (BDD) electrode. The hydroxyl radicals were quantified indirectly by assaying the samples from the HClO4 (0.1 M) electrolysis with a 10−4 M potassium permanganate solution. The investigations showed that the amount of hydroxyl radicals depends on the concentration of HClO4 and the current density. As for chlorine, a qualitative determination was carried out. A mixture of the electrolyte solution of HClO4 (0.1 M) + NaI (0.2 M) + 2 mL of hexane, taken in this order, leads to a purplish-pink coloration attesting to the presence of Cl2. The same test was carried out with NaBr and NaI giving pale and very pale pink colourations, respectively, showing that the intensity of the colouration depends on the strength of the oxidant present. In addition, oxidants were detected during the electrooxidation of metronidazole (MNZ). The results showed the participation of electrogenerated hydroxyl radicals. The generation of chlorine has also been proven. Furthermore, the degradation leads to a chemical oxygen demand (COD) removal rate of 83.48% and the process is diffusion-controlled.
文摘In this study, a homogeneous alkaline catalyst was used in the production of biodiesel from raw and refined castor oil feedstock. The effect of potassium hydroxide (KOH) as a catalyst between the two feedstocks, raw and refined castor oil was compared. The transesterification technique was utilized in this study, aiming to investigate the effect of different parameters, which include the reaction temperature, methanol-to-oil mole ratio, and catalyst concentration at a constant period of 90 minutes. The result revealed the performance of the KOH catalyst on raw castor oil yielded 98.49% FAME, which was higher than the refined castor oil which yielded 97.9% FAME. The optimal conditions obtained from refined castor oil were applied to raw castor oil because of the same properties. The fuel quality of castor oil and produced biodiesel were tested for physicochemical properties.
文摘With the full growth of energy needs in the world, several studies are now focused on finding renewable sources. The aim of this work is to optimise biofuel formulation from a mixture design by studying physical properties, such as specific gravity and kinematic viscosity of various formulated mixtures. Optimization from the mixture plan revealed that in the chosen experimental domain, the optimal conditions are: 40% for used frying oil (UFO), 50% for bioethanol and 10% for diesel. These experimental conditions lead to a biofuel with a density of 0.84 and a kinematic viscosity of 2.97 cSt. These parameters are compliant with the diesel quality certificate in tropical areas. These density and viscosity values were determined according to respective desirability values of 0.68 and 0.75.
文摘Organic molecules that exhibit long persistent luminescence (LPL) are rapidly gaining attention for a variety of applications. In this study, organic molecules with simple structures were selected and organic long persistent luminescence (OLPL) crystals were prepared. The crystal structure of the prepared OLPL crystal was elucidated and the guideline for the design of OLPL crystal was clarified. LPL was observed in OLPL crystals prepared with TMB as the guest molecule and 1,2-bis(diphenylphosphino)ethane as the host molecule. XRD measurements of the OLPL crystals suggest that the guest molecule is a solid solution substituted in the stable crystal structure of the host molecule in a lattice-shrinking direction.
文摘Coating slurries for making anodes and cathodes of lithium batteries contain a large percentage of solid particles of different chemicals, sizes and shapes in highly viscous media. A thorough mixing of these slurries poses a major challenge in the battery manufacturing process. Several types of mixing devices and mixing methods were examined. The conventional turbine stirrers or ball mill mixers could be adequately used for the preparation of anode slurries, but not suitable for cathode slurries. In this study, a newly three-dimensional mixer, in conjunction with a multi-stage mixing sequence was proposed. The mixing effectiveness was examined by means of rheological measurements and flow visualization techniques. Preliminary electrical performance results indicated that the battery obtained using the 3D mixing device with a multi-stage mixing sequence was more efficient to those obtained from conventional methods.
文摘Electrochemical impedance spectroscopy (EIS) in the l00 kHz-10 mHz frequency range was employed as the main electrochemical technique to study the corrosion protection behaviour of zinc rich epoxy paint in 3% NaCl solution. The EIS results obtained at the open-circuit corrosion potential have been interpreted using a model involving the impedance of particle to particle contact to account for the increasing resistance between zinc particles with immersion period, in addition to the impedance due to the zinc surface oxide layer and the electrical resistivity of the binder. Galvanic current and dc potential measurements allowed us to conclude that the cathodic protection effect of the paint takes some time to be achieved. The loss of cathodic protection is due to a double effect: the decrease of the Zn/Fe area ratio due to Zn corrosion and the loss of electric contact between Zn to Zn particles. Even when the cathodic protection effect by Zn dust become weak, the substrate steel is still protected against corrosion due to the barrier nature of the ZRP film reinforced by Zn.
文摘In this paper we demonstrate that the residual stress introduced by several different surface finishes affects the critical current density for passivation and the passive current density in the anodic polarization curve of austenitic stainless steel and that those critical current densities can be reduced by controlling the residual stress by applying a cavitating jet to the backs of specimens. The results show that the current density either increased or decreased depending on the surface finish, and that was decreased by introducing compressive residual stress for all surface finishes.
文摘In manufacturing process, it is necessary to measure change in CSD (Crystal Size Distribution) with time accurately because CSD is one of the most important indices that evaluate quality of products. FBRM (Focused Beam Reflectance Measurement) can measure CLD (Chord Length Distribution) in line, but CLD is different from CSD because of principle of FBRM. However, if CSD is determined beforehand, CLD can be calculated from the CSD with statistical method. First, when crystal shape is defined from the characteristic crystal size, the matrix of each crystal shape which transforms CSD into CLD in a uniform manner is calculated with Monte Carlo analysis. Characteristic crystal size is added to the variables defining chord length in order to avoid complex integrals and apply the change in crystal shape with characteristic crystal size to the transforming matrix. Secondly, CSD and CLD are actually measured in suspension of acetaminophen in ethanol and suspension of L-arginine in water to demonstrate the validity of 2 matrices. Lastly, these matrices are multiplied by some simple CSD models to test the properties of these matrices and demonstrate the utility of this transformation.
