Environmental performance of algal biofuel technology options

Considerable research and development is underway to produce fuels from microalgae, one of several options being explored for increasing transportation fuel supplies and mitigating greenhouse gas emissions (GHG). This work models life-cycle GHG and on-site freshwater consumption for algal biofuels over a wide technology space, spanning both near- and long-term options. The environmental performance of algal biofuel production can vary considerably and is influenced by engineering, biological, siting, and land-use considerations. We have examined these considerations for open pond systems, to identify variables that have a strong influence on GHG and freshwater consumption. We conclude that algal biofuels can yield GHG reductions relative to fossil and other biobased fuels with the use of appropriate technology options. Further, freshwater consumption for algal biofuels produced using saline pond systems can be comparable to that of petroleum-derived fuels.     

微波辅助回流提取葵花籽粕绿原酸的研究

以微波辅助回流提取的方法从葵花籽粕中提取绿原酸。研究了微波辅助提取绿原酸过程中料液比、微波辐射功率、乙醇体积分数以及提取时间对绿原酸得率影响的单因素试验,并在单因素试验基础上进行了正交试验,得出优化的微波辅助回流提取参数为:料液比1∶18、微波辐射功率390 W、乙醇体积分数35%和提取时间20 min,在此条件下绿原酸提取率达到94.6%、得率为2.11%。对提取的绿原酸产品进行抗氧化试验,结果表明葵花籽粕绿原酸对DPPH自由基有显著清除作用,其对DPPH自由基的EC50值为2.6 mg/L。     

豆粕混菌液体发酵制种技术试验研究

利用热带假丝酵母和枯草芽孢杆菌混菌发酵进行液体制种。结果表明:受接种量、豆粕含量和培养温度的影响,两株菌种菌数的增长速度具有相对一致的变化趋势;受培养时间的影响,热带假丝酵母菌先增后降,枯草芽孢杆菌先降后增;热带假丝酵母在pH3.5时菌数最大,枯草芽孢杆菌在pH4.5～7.5范围内适宜生长。在豆粕质量分数15%、葡萄糖质量分数1%、初始pH4.5的液体培养基上,两菌分别接种10%,在发酵温度28℃、摇床转速160r/min条件下培养5d,热带假丝酵母菌和枯草芽孢杆菌菌数达到最大,分别为752.5×106和264.2×107 cfu/ml。     

Storage stability of sterilized liquid extracts from pomegranate peel

Pomegranate marc, a byproduct of commercial juice production, has shown promise as a starting material for the recovery of health promoting phenolic compounds. The stability of aqueous extracts prepared from pomegranate marc was evaluated in preparation to directly using these extracts as nutraceuticals or food additives. The liquid extracts were produced under extraction conditions of 25 °C, water to peel ratio of 50 : 1 (w/w) for 2 min, and then sterilized at 121 °C for 10 s. Storage conditions tested included 3 different pH values (3.5, 5.0, and 7.0) and 2 packaging methods (no light and exposure to light). The extracts were evaluated for industrial (pH, total soluble solid content, and clarity), color, spectral, and antioxidant characteristics over a period of 180 d. The results showed that both pH value and packaging method significantly influenced the industrial and color characteristics of the extracts. The high pH had a negative effect on spectral and antioxidant characteristics. Therefore, the recommended storage conditions are low pH and with dark packaging to maintain the high storage stability. After 180 d of storage, extracts stored at low pH (3.5) in dark packaging still retained 67% and 58% of their total soluble phenolic concentration and antioxidant activity, compared with 61% and 43% for high pH (7.0) samples, and were composed of high concentrations of punicalagins A and B, gallic, and ellagic acids. PRACTICAL APPLICATION: The present research developed an effective recovery of phenolic compounds from pomegranate marc to be used as nutraceuticals or food additives. The aqueous extract product has good quality characteristics with high industrial and color stability, and total phenolic content and antioxidant activity, when stored at pH 3.5 in dark packaging for up to 180 d. The evaluation results of storage stability reported here are important for commercialization.     

超滤技术分离双低油菜ACE抑制肽及其性能研究

采用超滤技术对双低油菜酶解物中的ACE抑制肽进行了分离提纯研究,考核了分离参数对分离效果的影响,分析了不同分子质量段多肽HPLC肽谱的变化,研究了双低油菜高ACE抑制活性多肽的耐消化性、酸碱稳定性和耐热性。结果表明,超滤分离能明显提高双低油菜ACE抑制肽的活性,截留分子质量为3 ku的超滤膜透过液IC50值下降了15%,活性多肽回收率超过58%,酶解物中有4个高活性的组分峰,小于3 ku分子质量段的ACE抑制肽有良好的耐热性、酸碱稳定性和耐消化性。     

Implementation of moving TDM slots for voice transmission on Ethernet

The concept of moving time division multiplex (TDM) slots has been suggested as a method of avoiding collisions on an Ethernet system carrying voice and data packets. This paper describes a technique for implementing a type of moving TDM slot system with currently available VLSI Ethernet devices. The technique is hardware based and has the advantage of operating within the standard Ethernet parameters and of having a low cost of implementation.     

Platelet aggregation induced by a monoclonal antibody to the A1 domain of von Willebrand factor

Shear-induced platelet aggregation (SIPA) involves von Willebrand Factor (vWF) binding to platelet glycoprotein (GP)Ib at high shear stress, followed by the activation of alphaIIb beta3. The purpose of this study was to determine the vWF sequences involved in SIPA by using monoclonal antibodies (MoAbs) to vWF known to interfere with its binding to GPIb and to alphaIIb beta3. Washed platelets were exposed to shear rates between 100 and 4,000 seconds-1 in a rotational viscometer. SIPA was quantitated by flow cytometry as the disappearance of single platelets (DSP) in the sheared sample in the presence of vWF, relative to a control in the absence of shear and vWF. At a shear rate of 4,000 seconds-1, DSP was increased from 5.9% +/- 3.5% in the absence of vWF to 32.7% +/- 6.3% in the presence of vWF. This increase in SIPA was not associated with an elevation of P-selectin expression. vWF-dependent SIPA was completely abolished by MoAb 6D1 to GPIb and partially inhibited by MoAb 10E5 to alphaIIb beta3. Three MoAbs to vWF were compared for their effect on SIPA at 4,000 seconds-1 in the presence of vWF: MoAb 328, known to block vWF binding to GPIb in the presence of ristocetin, MoAb 724 blocking vWF binding to GPIb in the presence of botrocetin, and MoAb 9, an inhibitor of vWF binding to alphaIIbbeta3. Similar to the effect of MoAb 6D1, MoAb 328 completely inhibited the effect of vWF, whereas MoAb 9 had a partial inhibitory effect, as MoAb 10E5 did. In contrast, MoAb 724, as well as its F(ab')2 fragments, promoted shear-dependent platelet aggregation (165% of the DSP value obtained in the absence of MoAb 724), indicating that MoAb 724 was responsible for an enhanced aggregation, which was independent of binding to the platelet Fcgamma receptor. In addition, the enhancement of aggregation induced by MoAb 724 was abrogated by MoAb 6D1 or 10E5 to the level of SIPA obtained in the presence of vWF incubated with a control MoAb to vWF. Finally, the activating effect of MoAb 724 was also found under static conditions at ristocetin concentrations too low to induce platelet aggregation. Our results suggested that on binding to a botrocetin-binding site on vWF, MoAb 724 mimics the effect of botrocetin by inducing an active conformation of vWF that is more sensitive to shear stress or to low ristocetin concentration.     

Sensitization to morphine induced by viral-mediated gene transfer

Repeated administration of morphine sensitizes animals to the stimulant and rewarding properties of the drug. It also selectively increases expression of GluR1 (an AMPA glutamate receptor subunit) in the ventral tegmental area, a midbrain region implicated in morphine action. By viral-mediated gene transfer, a causal relation is shown between these behavioral and biochemical adaptations: Morphine's stimulant and rewarding properties are intensified after microinjections of a viral vector expressing GluR1 into the ventral tegmental area. These results confirm the importance of AMPA receptors in morphine action and demonstrate specific locomotor and motivational adaptations resulting from altered expression of a single localized gene product.     

Structural analysis of value creation in software service platforms

As software service platforms grow in number of users and variety of service offerings, it raises the question of how this phenomenon impacts the value obtained by users. This paper identifies system usability, service variety, and personal connectivity to be the major determinants that contribute to the value offered to users on mobile software service platforms. A structural equation model, which is based on utility theory, technology acceptance theory, and the theory of network externalities, has been constructed from seven observed constructs, reflecting the three determinants and the user value. The lower bound of user value is estimated through the user’s willingness-to-pay for services and the user’s willingness to spend time on using services. For the validation, a co-variance-based structural equation analysis has been conducted on online survey data of 210 users of mobile service platforms (e.g., Android, iOS). The results show that the number of services used and the number of active user connections were found to be the strongest constructs explaining user value. Perceived usefulness did not explain user value as much. In total, they can explain 49 % of the value that the user receives from the platform. The implication of this result is that users’ value from a software service platform cannot be explained by the technology acceptance model itself. Instead, an approach that, as used in this research, of integrating network externality theory, utility theory, and technology acceptance theory is necessary.     

Newly Synthesized Nonvacuum Processed High-k Polymeric Dielectrics with Carboxyl Functionality for Highly Stable Operating Printed Transistor Applications

Solution-processed polar hydroxyl containing polymers such as poly(4-vinylphenol) are widely utilized in organic filed-effect transistors (OFETs) due to their high dielectric constant (k) and excellent insulating properties owing to the crosslinking through their hydroxyl groups. However, hydroxyl functionalities can function as trapsites, and their crosslinking reactions decrease the k value of materials. Hence, in this study, new solution-processable copolymers containing both carboxyl and hydrophobic functionalities are synthesized. A fluorophenyl azide (FPA) based UV-assisted crosslinker is also employed to promote the movement of polar carboxyl groups toward the bulk region and the hydrophobic functionalities to the surface region, thereby maintaining the high-k characteristics and hydrophobic surface in thin film. Thus, the addition of an FPA crosslinker eliminates the trapsites on the surface, allowing a stable operation and efficient charge transport. Additionally, the solution-processability enables the production of uniform and thin films to yield OFETs with stable and low-voltage driving characteristics. The printed layers are also applied as gate dielectrics for floating gate memory devices and in integrated one-transistor-one-transistor based memory cells, displaying their excellent memory performance. The synthesis and fabrication strategies employed in this study can become useful guidelines for the production of high-k dielectrics for stable OFETs and other applications.