A New Tuning Method for Two-Degree-of-Freedom Internal Model Control under Parametric Uncertainty

Internal model control （IMC） yields very good performance for set point tracking, but gives sluggish response for disturbance rejection problem. A two-degree-of-freedom IMC （2DOF-IMC） has been developed to overcome the weakness. However, the setting of parameter becomes a complicated matter if there is an uncertainty model. The present study proposes a new tuning method for the controller. The proposed tuning method consists of three steps. Firstly, the worst case of the model uncertainty is determined. Secondly, the parameter of set point con- troller using maximum peak （Mp） criteria is specified, and finally, the parameter of the disturbance rejection con- troller using gain margin （GM） criteria is obtained. The proposed method is denoted as Mp-GM tuning method. The effectiveness of Mp-GM tuning method has evaluated and compared with IMC-controller tuning program （IMCTUNE） as bench mark. The evaluation and comparison have been done through the simulation on a number of first order plus dead time （FOPDT） and higher order processes. The FOPDT process tested includes processes with controllability ratio in the range 0.7 to 2.5. The higher processes include second order with underdarnped and third order with nonminimum phase processes. Although the two of higher order processes are considered as difficult processes, the proposed Mp-GM tuning method are able to obtain the good controller parameter even under process uncertainties.

Surface Morphology and Thermo-Electrical Energy Analysis of Polyaniline (PANI) Incorporated Cotton Fabric

With the exponential development in wearable electronics,a significant paradigm shift is observed from rigid electronics to flexible wearable devices.Polyaniline(PANI)is considered as a dominant material in this sector,as it is endowed with the optical properties of both metal and semiconductors.However,its widespread application got delineated because of its irregular rigid form,level of conductivity,and precise choice of solvents.Incorporating PANI in textile materials can generate promising functionality for wearable applications.This research work employed a straightforward in-situ chemical oxidative polymerization to synthesize PANI on Cotton fabric surfaces with varying dopant(HCl)concentrations.Pre-treatment using NaOH is implemented to improve the conductivity of the fabric surface by increasing the monomer absorption.This research explores the morphological and structural analysis employing SEM,FTIR and EDX.The surface resistivity was measured using a digital multimeter,and thermal stability is measured using TGA.Upon successful polymerization,a homogenous coating layer is observed.It is revealed that the simple pre-treatment technique significantly reduces the surface resistivity of Cotton fabric to 1.27 kΩ/cm with increasing acid concentration and thermal stability.The electro-thermal energy can also reach up to 38.2°C within 50 s with a deployed voltage of 15 V.The modified fabric is anticipated to be used in thermal regulation,supercapacitor,sensor,UV shielding,antimicrobial and other prospective functional applications.

Effect of surfactants and their blend with silica nanoparticles on wax deposition in a Malaysian crude oil

The present study investigated the wax deposition tendencies of a light Malaysian crude oil（42.4° API）, and the wax inhibiting potential of some surfactants and their blends with nanoparticles. With the knowledge that the majority of the wax inhibition research revolved around polymeric wax inhibitors, which cause environmental issues, we highlighted the potential of surfactants and their blend with SiO2 nanoparticles as wax deposition inhibitors. Different surfactants including oil-based, silane-based, Gemini and bio-surfactants were considered as primary surfactants. The primary surfactants and their respective blends at a concentration of 400 ppm were screened as wax inhibitor candidates using cold finger apparatus. The screening results showed a significant influence on the paraffin inhibition efficiency on wax deposition by using 400 ppm of silane-based surfactant, which decreased the wax deposition up to 53.9% as compared to that of the untreated crude oil. The inhibition efficiency among the silane-based surfactant（highest） and bio-surfactant（lowest）revealed an appreciable difference up to 36.5%. Furthermore, the wax from the treated sample was found to deposit in a thin gel-like form, which adhered inadequately to the surface of the cold finger. A further investigation by blending the 400 ppm silane-based surfactant with a 400 ppm SiO2 nanoparticle suspension in a load ratio of 3：1 found that the wax inhibition decreased up to 81% as compared to the scenario when they were not added. However, we have shown that the synergy between the silane-based surfactant and the nanoparticles is influenced by the concentration and load ratio of surfactant and nanoparticles, residence time, differential temperature and rotation rate.

以对二甲苯氧化为对苯二甲酸为例简要综述一级C–H键活化(英文)

The oxidation of para‐xylene to terephthalic acid has been commercialised as the AMOCO process(Co/Mn/Br) that uses a homogeneous catalyst of cobalt and manganese together with a corrosive bromide compound as a promoter. This process is conducted in acidic medium at a high tempera‐ture(175–225 °C). Concerns over environmental and safety issues have driven studies to find mild‐er oxidation reactions of para‐xylene. This review discussed past and current progress in the oxida‐tion of para‐xylene process. The discussion concentrates on the approach of green chemistry in‐cluding(1) using heterogeneous catalysts with promising high selectivity and mild reaction condi‐tion,(2) application of carbon dioxide as a co‐oxidant, and(3) application of alternative promoters. The optimisation of para‐xylene oxidation was also outlined.

Catalytic performance of cement clinker supported nickel catalyst in glycerol dry reforming

The paper reports the development of cement clinker-supported nickel （with metal loadings of 5 wt%, 10 wt%, 15 wt% and 20 wt%） catalysts for glycerol dry （CO2） reforming reaction. XRF results showed that CaO constituted 62.0% of cement clinker. The physicochemical characterization of the catalysts revealed 32-folds increment of BET surface area （SBET） with the addition of nickel metal into the cement clinker, which was also corroborated by FESEM images. Significantly, XRD results suggested different types of Ni oxides formation with Ni loading, whilst Ca3SiO5 and Ca2Al0.67Mn0.33FeO5 were the main crystallite species for pure cement clinker. Temperature-programmed reduction analysis yielded three domains of H2 reduction peaks, viz. centered at approximately 750 K referred to as type-Ⅰ peaks, another peaks at 820 K denoted as type-Ⅱ peaks and the highest reduction peaks, type-Ⅲ recorded at above 1000 K. 20 wt% Ni was found to be the best loading with the highest XG and H2 yield, whilst the lowest methanation activity. Syngas with lower H2/CO ratios （0.6 to 1.5） were readily produced from glycerol dry reforming at CO2-to-Glycerol feed ratio （CGR） of unity. Nonetheless, carbon deposit comprised of whisker type （Cv） and graphitic-like type （Cc） species were found to be in majority on 20 wt%Ni/CC catalysts.

Characterization of La-promoted Ni/Al_2O_3 catalysts for hydrogen production from glycerol dry reforming

In the current paper, dry(CO2)-reforming of glycerol, a new reforming route, was carried out over alumina(Al2O3)-supported, non-promoted and lanthanum-promoted nickel(Ni) catalysts. Both sets of catalysts were synthesized via a wet co-impregnation procedure. Physicochemical characterization of the catalysts showed that the promoted catalyst possessed smaller metal crystallite size, hence higher metal dispersion compared to the virgin Ni/Al2O3catalyst. This was also corroborated by the surface images captured by the FESEM analysis. From temperature-programmed calcination analysis, the derivative weight profiles revealed two peaks, which represent a water elimination peak at a temperature range of 373 to 473 K followed by nickel nitrate decomposition from 473 to 573 K. In addition, BET surface area measurements gave 85.0 m2 g-1for the non-promoted Ni catalyst, whilst the promoted catalysts showed an average of 1% to 6% improvement depending on the La loadings. Significantly, reaction studies at 873 K showed that glycerol dry reforming successfully produced H2. The 2%La-Ni/Al2O3catalyst, which possessed the largest BET surface area, gave an optimum H2generation(9.70%) at a glycerol conversion of 24.5%.

Aphrodisiac potential of Polyalthia bullata (Tongkat Ali) in fowl

Objective:To study the aphrodisiac potential of Polyalthia(P.)bullata in fowl.Methods:In this study,testosterone,as an indicator of the aphrodisiac potential of P.bullata,was investigated for its release from TM3 Leydig cells grown in vitro and in 4 fowls given capsules containing P.bullata at a dose of 10 mg in each capsule twice a day,for 50 days.In the latter in vivo evaluation,mating behaviours were additionally determined after the treated fowls were released to the individual hens,and their testes and liver were dissected for histological examinations.Blood drawn from the fowls was assessed for any changes in diagnostic parameters.Results:In the in vitro test(TM3 Leydig cells),P.bullata was able to increase testosterone to 0.48 nmol/L within 72 h of incubation,compared to the untreated control with only 0.18 nmol/L,i.e.,an increase of 170%.In the in vivo test,outcomes in the fowls dosed with P.bullata showed similar positive elevations of testosterone to(9.72±1.10)nmol/L in comparison to the controls that showed a level of only(4.05±0.84)nmol/L.Total frequencies of mating behaviours were observed(wing flapping,body shakes,crowing and beak pecking)to be 23 counts for the test compared to only 15 for the control fowls.Histological examination of the male reproductive organs provided evidence of testosterone boosting based on an observable increase in the activity at the seminiferous tubules of testis tissues without any damaging effects,compared to the controls.In the nine diagnostic blood parameters assessed,including alanine aminotransferase,aspartate aminotransferase,and gamma glutamyltransferase,none was remarkably elevated compared to the controls.The histological changes in the liver were not severe and mainly consisted of only localized moderate but recoverable obstructions and swellings of the vessels and tubules.Conclusions:P.bullata is able to boost testosterone both in vitro and in vivo,with no acute toxicities.

Application of Intuitionistic Z-Numbers in Supplier Selection

Intuitionistic fuzzy numbers incorporate the membership and non-membership degrees.In contrast,Z-numbers consist of restriction components,with the existence of a reliability component describing the degree of certainty for the restriction.The combination of intuitionistic fuzzy numbers and Z-numbers produce a new type of fuzzy numbers,namely intuitionistic Z-numbers(IZN).The strength of IZN is their capability of better handling the uncertainty compared to Zadeh's Z-numbers since both components of Z-numbers are charac-terized by the membership and non-membership functions,exhibiting the degree of the hesitancy of decision-makers.This paper presents the application of such numbers in fuzzy multi-criteria decision-making problems.A decision-making model is proposed using the trapezoidal intuitionistic fuzzy power ordered weighted average as the aggregation function and the ranking function to rank the alternatives.The proposed model is then implemented in a supplier selection problem.The obtained ranking is compared to the existing models based on Z-numbers.The results show that the ranking order is slightly different from the existing models.Sensitivity analysis is performed to validate the obtained ranking.The sensitivity analysis result shows that the best supplier is obtained using the proposed model with 80%to 100%consistency despite the drastic change of criteria weights.Intuitionistic Z-numbers play a very important role in describing the uncertainty in the decision makers’opinions in solving decision-making problems.

Immunosuppressive and antibacterial activities of dihydromorin and norartocarpetin isolated from Artocarpus heterophyllus heartwoods

Objective:To evaluate the immunosuppressive effect on human phagocytes and antibacterial activity of dihydromorin and norartocarpetin isolated from Artocarpus heterophyllus heartwoods.Methods:Dihydromorin and norartocarpetin were isolated from Artocarpus heterophyllus heartwoods.A modified Boyden chamber was used to determine the chemotactic activity of human phagocyte.The respiratory burst was evaluated by chemiluminescence assay.Myeloperoxidase(MPO)activity was quantified using a colorimetric assay.The broth microdilution method was performed to assess their antibacterial activity.Results:Dihydromorin exhibited potent inhibitory effect on the chemotactic activity of polymorphonuclear neutrophils(PMNs)with an IC50 value of 5.03μg/mL.Dihydromorin also inhibited reactive oxygen species production of whole blood cells,PMNs,and monocytes with IC50 values of 7.88,7.59 and 7.24μg/mL,respectively.Interestingly,dihydromorin also strongly inhibited the MPO activity of PMNs with an IC50 value of 5.24μg/mL,which was lower than indomethacin(24.6μg/mL).Molecular docking of dihydromorin and crystal structure of MPO showed that dihydromorin had close interaction with key amino acid residues such as Arg239 and Gln91.Antibacterial activity assay showed that only dihydromorin had a strong effect against Streptococcus pyogenes with MIC and MBC values of 15.62 and 31.25μg/mL,respectively.Conclusions:The results suggest that dihydromorin could be developed as an anti-inflammatory and antibacterial agent.

Formulation of Mixed-Matrix Membrane (PSF/Zeolite) for CO<SUB>2</SUB>/N<SUB>2</SUB>Separation: Screening of Polymer Concentration

This research investigates the permeability of CO2 and N2 as well as selectivity of CO2 over N2 of polysulfone (PSF) mixed matrix membranes filled with zeolite 4&Aring particles. The membranes were prepared by solution-casting method and utilized to determine the permeation rates of N2 and CO2. It was characterized by FTIR and the gas separation performance was analysed by Design of Expert (DOE) method. FTIR result revealed the intensity of peak for sulfone S=O vibration at 1322 cm-1;it was related to O=S=O bound of polysulfone in the sample. The single concentration variable has low outcome, however the mixture concentration interaction was effectively to lead better selectivity of CO2 over N2. In terms of interaction between mixture concentrations, interaction between PSF and N-Methyl-2-pyrrolidone (NMP) has considerable effect on the permeability of CO2 with the highest F value of 0.46 membrane. NMP exhibited a high degree of polarity and hydrogen bonding which led to effect of selective skin and permeation rate. The model regression equations were developed as the potential use for screening the permeability of CO2 and N2 based on the deviation effect of polymer concentration.

Nutraceuticals as potential therapeutic agents for colon cancer: a review

Colon cancer is a world-wide health problem and the second-most dangerous type of cancer,affecting both men and women.The modern diet and lifestyles,with high meat consumption and excessive alcohol use,along with limited physical activity has led to an increasing mortality rate for colon cancer worldwide.As a result,there is a need to develop novel and environmentally benign drug therapies for colon cancer.Currently,nutraceuticals play an increasingly important role in the treatment of various chronic diseases such as colon cancer,diabetes and Alzheimer's disease.Nutraceuticals are derived from various natural sources such as medicinal plants,marine organisms,vegetables and fruits.Nutraceuticals have shown the potential to reduce the risk of colon cancer and slow its progression.These dietary substances target different molecular aspects of colon cancer development.Accordingly,this review briefly discusses the medicinal importance of nutraceuticals and their ability to reduce the risk of colorectal carcinogenesis.

Insoluble additives for enhancing a blood-like liquid flow in micro-channels

This study introduces an approach for flow enhancement in the bloodstream using insoluble additives as non-degradable drag reducing agents that can replace the polymeric soluble additives. An open micro-channel liquid flow system with three different channel sizes was assembled and used to test the drag reduction performances of the solutions investigated. Three different nano- powders （with five different addition concentrations） were investigated and used to form solutions of artificial blood with blood-like rheological properties. The experimental results showed that the optimum drag reduction performance was achieved using bismuth III oxides （65%） for a 200 ppm concentration solution flowing through a 100 μm channel, while titanium IV oxides and fumed silica achieved 57 and 55% drag reduction for a 200 ppm concentration solution flowing in a 50 ktm channel, respectively.

A mixed acid methodology to produce thermally stable cellulose nanocrystal at high yield using phosphoric acid

Cellulose nanocrystal(CNC)with distinctive shape-morphology,enhanced thermal stability and dispersibility is essential for overcoming the challenges in processing polymer/CNC nanocom-posites through melt compounding at elevated temperatures.This study shows a mixed acid hy-drolysis method to produce CNC with improved thermal stability and high productivity.The use of phosphoric acid(H_(3)PO_(4)),as a mild acid,in combination with a strong acid either sulphuric acid(H_(2)SO_(4))or hydrochloric acid(HCl)leads to reduced use of strong acids and low impact on our environment.The influences of acid combination and sequence of addition on the production yield were investigated by retaining the proportion of H_(3)PO_(4)to corrosive acid(H_(2)SO_(4)and HCl)4 to 1,and solid to liquid ratio 1꞉75.This methodology has enabled to isolate CNC with higher thermal stability,dispersibility and productivity in terms of amount acid used 1 g of CNC,as compared with single acid hydrolysis.The CNC produced using the combination of H_(3)PO_(4)and HCl exhibits high thermal stability,dispersibility and rod-like shape morphology with length and width of(424±86)and(22±3)nm,respectively.Moreover,this approach has reduced H_(3)PO_(4)consumption by 54%as compared with single acid hydrolysis method for the production of same amount of CNC.

Achievement of high rate nitritation with aerobic granular sludge reactors enhanced by sludge recirculation events

A ratio control strategy has been used to demonstrate the feasibility of this automatic control procedure for the achievement of stable full and partial nitritation. The control strategy assured constant ratio between the dissolved oxygen （DO） and the total ammonia nitrogen （TAN） concentrations in the bulk liquid of aerobic granular sludge reactors operating in continuous mode. Three different set-ups with different reactor capacities were used （3, 110, and 150L）. High strength synthetic wastewaters and reject water were tested with similar performance. Achieved nitrogen loading rates ranged between 0.4 and 6.1 kgN· m^-3·d^-1, at temperatures between 20℃ and 30℃. 1Granular sludge and nitritation were stable in the long term continuous operation of the reactors. Suitable stable effluent for Anammox has been obtained using the desired TAN setpoint （i.e. 50% of influent ammonium oxidation）. An existing biofilm model devel- oped incorporating the implemented control loops and validated in a previous publication was used to investigate the effects of the ammonium concentration of the influent and the biofilm density on the achievement of full nitritation. The model demonstrated how sludge recirculation events led to a stable and significant increase of the biomass concentration in the reactor, which in turn resulted in the achievement of high nitrogen loading rates, due to the action of the control strategy. The model predicted an enhancement of stable full nitritation at higher ammonium concentrations in the influent. Poor influence of the biofilm density in the achievement of full nitritation was predicted with the model.

Induction of bioactive compound composition from marine microalgae(Lyngbya sp.)by using different stress condition

Objective:To the effect of salinity stress on the production of microalgae(Lyngbya sp.)and chlorophyll pigments in the growth medium.Methods:Stress was investigated by using green algae strains Lyngbya sp.in response to change bioactive compounds without any modification of cell growth and biomass production rate.The different stress conditions like 10%-40%were analyzed.Results:During the stress condition,various biochemical and microbiological assays were monitored.The photochemical composition was evaluated by GC-MS studies.The studies expressed that 30%higher salinity stress was suitable for high phytochemical production rate including chlorophyll content.Conclusions:Our study indicates the wide range of salinity stress to enhance the growth on microalgae culture and enhance the production of major secondary metabolites.

Studies on in-vitro antioxidant activity of marine edible seaweeds from the east coastal region of Peninsular Malaysia using different extraction methods

Objective:To determine the antioxidant activity of two edible marine seaweeds Eucheumacottonii and Padina sp..Methods:The two extraction methods such as conventional and soxhlet extraction were used to isolate the secondary metabolites using methanol as a solvent medium.Total phenolic content of crude seaweeds extract were analysed by standard FC method.The different antioxidant assays DPPH,ferric reducing antioxidant power and β-carotene bleaching assays confirmed the antioxidant activities.Results:with expressed higher total phenolic content in the seaweeds extract.Also β-carotene bleaching assay lower activity compare with BHT as reference control.Additionally IR spectra showed the phenolic related functional groups are present in the solvent extract.The phenolic related compounds are mainly responsible for higher rate of antioxidant activity.Conclusions:DPPH and ferric reducing antioxidant power assays showed the positive correlation higher phenolic contents than the Eucheuma cottonii.And also the soxhlet extraction showed higher yield and better radical scavenging activity compared to conventional method.Moreover the studies confirmed both seaweeds are an effective candidate for the control the free radical scavenging activity.

Efficiency enhancement of building multi-layer solar collector with SiO2–TiO2 hybrid nanofluids

Due to the depletion of conventional energy sources and its limitless resources,solar energy is currently being considered as a viable alternative,especially for water heating systems.The thermal performance of multilayer solar collectors for water heating systems can be improved further by introducing hybrid nanofluids as advanced fluids.This study demonstrates the utilisation of hybrid nanofluids in heating systems by employing a multilayer absorber solar collector.The SiO2–TiO2 hybrid nanofluids at volume concentrations up to 2.0%were tested at various flow rates(1.7 to 3.7 LPM)and solar radiation intensities(250 to 1000 W/m2).The thermal performance of the solar collector was assessed by measuring the temperature variation,heat loss,and overall efficiency of the collector.At the optimal volume concentration,the temperature difference for solar collectors employing SiO2–TiO2 hybrid nanofluids increased significantly.The optimal volume concentration of 1.5%yields a maximum temperature difference of 9.5°C.In addition,the efficiency and fluid temperature of the solar collector containing hybrid nanofluids have been enhanced by 22%and 37%,respectively.The SiO2–TiO2 hybrid nanofluids with the optimal volume concentration of 1.5%were therefore recommended for maximum efficiency in the solar collector.

Shelf life evaluation of formulated cookies from Hanjeli (Coix lacryma-jobi L.) and Moringa leaf flour (Moringa oleifera)

Hanjeli(Coix lacryma-jobi L.)and moringa leaf(Moringa oleifera)remain underutilised despite their high nutritional value for food.In the present research,cookies made from hanjeli(Coix lacryma-jobi L.)with moringa leaf flour(Moringa oleifera)have been developed.Hanjeli cookies were measured for nutritional composition and shelf life assessment.The shelf life evaluation of hanjeli-moringa cookies was calculated using two approaches,which were accelerated shelf life testing(ASLT)methods with critical moisture content and the Arrhenius method.The results of the nutritional composition analysis showed that hanjeli-moringa cookies contain protein(9.14%),fat(24.67%),carbohydrates(61.62%),crude fibre(4.85%),and energy(505.01 Kcal).Using the Arrhenius method,the shelf life of hanjeli-moringa cookies was 95.46 days at room temperature and 97.63 days at 20℃.Meanwhile,the shelf life of cookies using the critical moisture content approach was 170.57 days.Shelf life is influenced by initial moisture content,critical water content of the product,packaging surface area and permeability,saturated vapour pressure,and slope sorption isotherm curve.The formulated cookies have significant amounts of nutrients that are acceptable and safe for consumption,with guaranteed desirable sensory properties.The result of this study shows that hanjeli-moringa cookies can be used as an alternative food for people who need high energy in a practical way of serving or ready to eat.