Characterization and transesterification of fresh water microalgal oil

In the present investigation bulk algal biomass was collected from different natural water bodies of Himachal Pradesh, India. Maximum oil content of consortia was estimated at 3.7% and major fatty acids were oleic acid (18:1), palmitic acid (16:0), linoleic acid (18:2), and palmitoliec acid (16:1), which are the main constituents of biodiesel. Viscosity of algae oil was found to be high and transesterification was done by basic, microwave-, and ultrasonication-assisted methods. Maximum conversion from algal oil to fatty acid methyl esters was obtained by ultrasonication-assisted transesterification (71.5%), whereas microwave-assisted and basic transesterification was 58.6 and 51.3%, respectively.     

Anomalous electrical transport properties of PVA–Ag composite films below room temperature

The direct current (dc) and alternate current (ac) electrical transport property of polyvinyl alcohol–silver (PVA–Ag) composites has been investigated within a temperature range of 77 ≤ T ≤ 300 K and in the frequency range of 20 Hz to 1 MHz in the presence as well as in the absence of a transverse magnetic field up to 1 T. The dc conductivity follows variable range hopping model. The magnetoconductivity of the samples undergoes a change from negative to positive values with the incorporation of Ag in PVA matrix, which can be interpreted by the dominancy of the forward interference effect prevailing over the wave function shrinkage effect. The ac conductivity follows a power law of frequency, whereas the temperature dependence of frequency exponent “s” can be explained by correlated barrier hopping model. The dielectric behavior of the samples has been governed by the grain and interfacial grain boundary resistance and capacitance. Two activation behaviors are observed from the analysis of grain and interfacial grain boundary contributions. POLYM. COMPOS., 33:1941–1950, 2012. © 2012 Society of Plastics Engineers     

Maximizing Parallel Testing in an FM Receiver

High volume production environments create great challenges for production testing and verification of Radio Frequency (RF) devices. In this environment, much emphasis is put on parallel testing, or the ability to test multiple devices at the same time using a single tester. In order for this parallelism to become a reality, there is a need for production RF tests to be simplified and reduced to requiring only the simplest test stimulus and analysis. In this paper, we present a new method of measuring the performance of a Frequency Modulation (FM) receiver that requires only a continuous wave signal input in order to eliminate the more costly Signal-to-Noise Ratio test. Using this new technique we will then demonstrate how simplifying this test and adding frequency diversity enables testing of up to 8 devices in parallel using a single tester.     

Sensory evaluation of black pigmented rice (Oryza sativa cv. Poireton) wine fortified with probiotic Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 using fuzzy logic

Rice wine was prepared in the laboratory from a black pigmented rice (cv. Poireton) using standardized methodology. The wine was fortified with the probiotic strains Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 and allowed to undergo a storage period of 28 days at 4°C. These rice wines were compared with a commercial wine used as a standard reference wine. A panel consisting of 30 judges performed the sensory evaluation. The scores obtained were based on the quality attributes of colour, taste, aroma and alcoholic strength. Analysis of the sensory scores and ranking of the different samples were performed using fuzzy analysis. The quality attributes were also ranked according to their importance in the overall acceptability. Colour and alcoholic strength were accorded the highest importance, compared with aroma and taste, as quality attributes. The rice wines were rated as ‘not satisfactory’, ‘fair’, ‘medium’, ‘good’ and ‘excellent’ on the sensory scale. Out of the wines prepared, black pigmented rice wine fortified with L. acidophilus was the most acceptable and was ranked as ‘good’, which was also at par with the commercial wine. On the other hand, black pigmented rice wine fortified with L. sakei and black pigmented rice wine fortified with L. acidophilus and L. sakei were ranked in the ‘satisfactory’ category followed by the unfortified wine ranked in the ‘fair’ category. Copyright © 2015 The Institute of Brewing & Distilling     

Efficiency enhancement in organic solar cells with ferroelectric polymers

The recombination of electrons and holes in semiconducting polymer-fullerene blends has been identified as a main cause of energy loss in organic photovoltaic devices. Generally, an external bias voltage is required to efficiently separate the electrons and holes and thus prevent their recombination. Here we show that a large, permanent, internal electric field can be ensured by incorporating a ferroelectric polymer layer into the device, which eliminates the need for an external bias. The electric field, of the order of 50 V μm(-1), potentially induced by the ferroelectric layer is tens of times larger than that achievable by the use of electrodes with different work functions. We show that ferroelectric polymer layers enhanced the efficiency of several types of organic photovoltaic device from 1-2% without layers to 4-5% with layers. These enhanced efficiencies are 10-20% higher than those achieved by other methods, such as morphology and electrode work-function optimization. The devices show the unique characteristics of ferroelectric photovoltaic devices with switchable diode polarity and tunable efficiency.     

Carotid-jugular arteriovenous fistula: a case report of an iatrogenic complication following internal jugular vein catheterization for hemodialysis access

We report a case of diabetic end-stage renal disease patient who presented with a right common carotid artery jugular arteriovenous fistula as a complication of the insertion of a polyurethane double-lumen hemodialysis catheter into the right internal jugular vein .On physical examination of the neck, a pulsating mass with a palpable thrill and a bruit was noted in the right subclavicular region. The diagnosis was confirmed by color doppler ultrasonography of the neck and carotid angiography. The review of the literature suggests the occurrence of this complication as rather rare. The fistula was successfully repaired surgically. It is emphasized that while securing the access, a thorough physical examination with a special emphasis on seeking any neck swellings, thrill, and bruit along with routine use of vascular doppler for securing dialysis access is recommended.     

烧结工序中转炉渣的优化利用

钢铁厂产生的矿渣中很大一部分来自氧气顶吹转炉(LD转炉)和吹氧转炉工序.LD工序的主要目的是将熔融的铁水和废钢转化为优质钢.在印度,每年产生的熔融钢渣超过400～450万t.总体看来,生产每吨钢会产生150～200 kg的钢渣,对这些钢渣的处理已经成为了严重的环境问题.金达尔钢公司是年产700万t的联合钢厂,每天产生钢渣3 200 t,其中2 000～2 500 t来自LD转炉.LD转炉渣中含有47.75%的CaO,22.0%的Fe以及8.22%MgO,由于CaO含量很高,LD转炉渣可直接替代烧结工序中的生石灰.目前在实验室范围已进行了一些研究,以确定烧结工序中所允许的LD转炉渣的最大投加量以及转炉渣的投加对烧结产率和性能的影响.实验中,LD转炉渣在烧结矿里的添加量从0依次到60 kg/t.随着添加率的增大,烧结料层温度的降低致使FeO含量降低,而烧结配矿中烧损的降低以及由于避免了石灰石煅烧过程带来的的重量损失,使得烧结产率上升.与此同时,LD转炉渣中缺少自由的CaO,使烧结矿强度及还原粉化指数变差,可参加反应的CaO的减少也导致了铁酸钙相减少,及残存Fe2O3自由相增加.试验结果最终得出:烧结矿中LD转炉渣的投加量为30～35 kg/t时,可获得预期的烧结矿性能.     

Modeling evidence in support of coagulative nucleation theory

An extensive lumped model was developed for emulsion polymerization. It incorporated all of the complex processes: aqueous‐phase radical balances for all radical species arising from initiator decomposition and from exit; determination of radical number inside the particles by balance among rates of radical entry into, exit from, and termination inside the particles; determination of the monomer concentration inside the particles and in the aqueous phase by a thermodynamic equation; and particle formation by micellar, homogeneous, and coagulative nucleation. Model validation was done for the system with styrene (monomer), potassium persulfate (initiator), and sodium dodeceyl sulfate (emulsifier) and for the variables, which included the duration of nucleation, conversion at the end of nucleation, and total number of particles formed. The validation process revealed that coagulation during nucleation needed to be included in the model, even for emulsifier concentrations above the critical micelle concentration. The model predictions were in good quantitative agreement with the experimental data. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.