Performance and economic analysis of air flow windows in a tropical climate

An experimental study was conducted in Thailand to determine the thermal performance of twin glazed windows with dynamic insulation. The effects of blinds situated either between or outside the glazing were analysed. With an external blind, the heat transfer coefficient was 1–25 W/m²°C with natural convection and 0–6 W/m²°C for a flow of 20m³/h (glass area = 2–16m²). The solar flux transmitted was evaluated analytically and experimentally depending on the blind's position. An economic study was performed on a six-sotrey air-conditioned building in Thailand. It showed in tropical countries that it may be more economical to use air flow windows than to have tinted single or double glass windows.     

Rhinacanthus nasutus Extracts Prevent Glutamate and Amyloid-β Neurotoxicity in HT-22 Mouse Hippocampal Cells: Possible Active Compounds Include Lupeol, Stigmasterol and β-Sitosterol

The Herb Rhinacanthus nasutus (L.) Kurz, which is native to Thailand and Southeast Asia, has become known for its antioxidant properties. Neuronal loss in a number of diseases including Alzheimer's disease is thought to result, in part, from oxidative stress. Glutamate causes cell death in the mouse hippocampal cell line, HT-22, by unbalancing redox homeostasis, brought about by a reduction in glutathione levels, and amyloid-β has been shown to induce reactive oxygen species (ROS) production. Here in, we show that ethanol extracts of R. nasutus leaf and root are capable of dose dependently attenuating the neuron cell death caused by both glutamate and amyloid-β treatment. We used free radical scavenging assays to measure the extracts antioxidant activities and as well as quantifying phenolic, flavonoid and sterol content. Molecules found in R. nasutus, lupeol, stigmasterol and β-sitosterol are protective against glutamate toxicity.     

Role of Surface Area, Primary Particle Size, and Crystal Phase on Titanium Dioxide Nanoparticle Dispersion Properties

Characterizing nanoparticle dispersions and understanding the effect of parameters that alter dispersion properties are important for both environmental applications and toxicity investigations. The role of particle surface area, primary particle size, and crystal phase on TiO₂ nanoparticle dispersion properties is reported. Hydrodynamic size, zeta potential, and isoelectric point (IEP) of ten laboratory synthesized TiO₂ samples, and one commercial Degussa TiO₂ sample (P25) dispersed in different solutions were characterized. Solution ionic strength and pH affect titania dispersion properties. The effect of monovalent (NaCl) and divalent (MgCl₂) inert electrolytes on dispersion properties was quantified through their contribution to ionic strength. Increasing titania particle surface area resulted in a decrease in solution pH. At fixed pH, increasing the particle surface area enhanced the collision frequency between particles and led to a higher degree of agglomeration. In addition to the synthesis method, TiO₂ isoelectric point was found to be dependent on particle size. As anatase TiO₂ primary particle size increased from 6 nm to 104 nm, its IEP decreased from 6.0 to 3.8 that also results in changes in dispersion zeta potential and hydrodynamic size. In contrast to particle size, TiO₂ nanoparticle IEP was found to be insensitive to particle crystal structure.     

Effect of Pt or Pd doping on stability of TiO2 nanoparticle suspension in water

Stability of suspensions of TiO₂ nanoparticles synthesized by the flame aerosol reactor (FLAR) could be altered by doping TiO₂ nanoparticles with Pt, Pd, or Pt–Pd dopants. It was found that doping of TiO₂ with Pd or Pt could contribute to the control of the agglomeration of TiO₂ suspended in water. With the change of doping content, the isoelectric point (IEP) of stable TiO₂ suspension decreased gradually from 5 to 3.6 while the specific surface area was increased from 43.27 to 60.84 m²/g. With pH > 6.0, 2 wt% Pt–Pd/TiO₂ suspension exhibited the lowest agglomeration behavior. The plausible intrinsic structures of Pt, Pd, and Pt–Pd doped TiO₂ nanoparticles were proposed and discussed with respect to their IEP based on the DLVO theory.     

Optimization of Micro Crystalline Cellulose Production from Corn Cob for Pharmaceutical Industry Investment

MCC （micro crystalline cellulose） is a very important product in pharmaceuticals, foods, cosmetics and other industries. MCC can be made from any natural cellulose materials that have high content of cellulose ranging from pure cellulose, commercial grade cellulose to lignocellulosic materials. In this work, Beeswing （-20 L） and Chaff （5/8） which are the parts of corn cobs were used as raw materials to produce MCC via alkaline degradation, bleaching and hydrolysis. The optimum conditions of alkaline degradation, bleaching and hydrolysis were studied. MCC samples that prepared from -20 L and 5/8 were characterized through XRD （X-ray diffraction）, SEM （scanning electron microscopy） and compared with the commercial MCC （Avicel PH 101）. The results show that the degree of crystallinity of alkaline degradation, bleaching and hydrolysis obtained at 10% of NaOH 95 ~C for 2 h, NaCIO21.5 g 10% of acetic acid 0.5 mL 70 ~C for 2 h, 2 N of HC1, 105 ~C for 1 h showed maximum values which are 77.07%, 75.07% and 86.84%, respectively. The degree of crystallinity and the morphology of prepared MCC correspond to that of Avicel PH 101 industrial investment has been studied, the benefits of micro crystalline cellulose production （MCC） is 3,447 baht/kg. The investment of the plant is 7,263,514 baht and the breakeven point is around 6 years.     

Characterization of doped TiO2 nanoparticle dispersions

Nanomaterial suspensions with different dopant types and compositions were investigated to examine their effects on agglomeration through the measurement of hydrodynamic diameter (HD), surface charge, and isoelectric point (IEP). Four different types of nanoparticles, all synthesized by a flame aerosol reactor, were considered for the analysis. The nanoparticles considered were pristine TiO₂, Cu–TiO₂, V–TiO₂, and Pt–TiO₂ with dopant concentrations ranging from 1 to 6 wt%. Measurements were conducted over a broad range of pH (3–11) and ionic strengths (0.001–0.1 M) to understand the roles of pH and ionic strength (IS) on dispersion characteristics. Calculations were made using the classical DLVO theory to explain the agglomeration behavior. The results indicate that dopant addition can change surface charge, hydrodynamic diameter, and shift the IEP to higher or lower pH than pristine TiO₂, depending on the type of dopant and composition. Vanadium and platinum doping shifted the IEP to lower pH values, whereas copper doping shifted it to higher pH values. For each of the nanoparticles considered, pH and IS were found to have significant effects on the surface charge and HD, which were also verified by calculation from DLVO theory.     

Development of Porous Spherical Cellulose Bead Production from Corn Cob as an Exfoliating Agent for Cosmetic Industries

The aim of this research was to develop the porous spherical cellulose production from corn cob as an exfoliating agent for cosmetic industries. In process development of the porous spherical cellulose production from corn cob, it was found that alkaline extraction with 10% sodiumhydroxide gave 85.86% purity of cellulose and the crystallinity index of the pulp of 76.08%. Then, the obtained pulp was extracted with acid sodium chlorite. It was found that the acid sodium chlorite extraction increased the cellulose from 85.86% to 91.86%. The obtained pulp was hydrolyse dwithdilute hydrochloric solution. The result shows that the crystallinity increased from 71.13% to 86.31% with smaller crystallite size compared to that obtained acid sodium chlorite extraction. The hydrolysis pulp was used to prepare porous spherical cellulose which has homogeneous and rough surface. The porosity and pore volume of the porous spherical cellulose increased when the amount of calcium carbonate as porogen was increased. The porous spherical cellulose was prepared from the optimized conditions and the physical and chemical properties were analysed and compared with standard commercial beads （Sephadex G-25）. It was found that the porous spherical cellulose had particle size and pH value similar to the standard value. Hazardous substances such as arsenic, lead and mercury were not found in the obtained porous spherical cellulose. The consumers test shows that 87~/＇0 of consumers accepted the product and the overall complacency was great.