Sintered electrospun poly(ɛ-caprolactone)–poly(ethylene terephthalate) for drug delivery

Electrospinning has the inherent advantage of being able to achieve molecular mixing of polymers having substantially different melting points. Electrospun poly(ɛ-caprolactone)–poly(ethylene terephthalate) (PCL:PET) capsules are densified by sintering to enable drug encapsulation. Proton and diffusive nuclear magnetic resonance, as well as a selective dissolution, suggest an absence of reaction between the two polymers. Sintering at 100 °C successfully densifies 88.89:11.11 and 75:25 PCL:PET blends. Following sintering, the otherwise dense 75:25 composition retains electrospun features and exhibits some “memory” of its previous state. Sintering increases UTS approximately eightfold versus as-spun values for 88.89:11.11 and 75:25. Elongation increases sixfold and twofold and modulus 44- and 69-fold for the 75:25 and 88.89:11.11 samples, respectively. Differential scanning calorimetry suggests a postsintering structure of nanoscale PET dispersed in PCL along the original fiber directions. Selective PCL removal from dense blends shows that fibrous characteristics remain. An internal shish–kebab-like structure is also present in as-spun 75:25 PCL:PET. Water absorption of hydrophobic oil-containing capsules is approximately zero after 49 days. In contrast, hydrophilic (HPI) oils allow substantial water uptake. Unsurprisingly, there is no release of a model drug from the hydrophobic carrier. HPI oil provides linear (zero-order) release inversely proportional to PET from the 88.89:11.11 and 75:25 ratios. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47731.     

Ordering in disguise: digital integration in built-environment practices

ABSTRACT

The digital integration of built-environment practices aims to bridge a large variety of organizations to improve building delivery and operation. However, recent research on building information modelling (BIM) reported organizational challenges arising from digital integration. This suggests a need to develop a critical perspective on digital-integration-driven organizational change. Adopting a practice-based approach, this paper exposes the practice-level phenomenon responsible for the ongoing change to develop a critical understanding and enable better interventions. The concepts of ‘simplification’ and ‘systematization’ of digital integration are developed from previous literature and then used to explore and interrelate the practice-level experiences of digital integration (i.e. the experience of the change from within) and the emerging patterns of interactions (i.e. the picture of the change from outside) in a BIM-enabled design project. The concept of ‘ordering in disguise’ is proposed to capture this phenomenon. It shows that practitioners experience digital integration as various task-specific instances of unresponsive technology. However, they are unaware that their ongoing efforts to accommodate it actually further reinforce digital integration’s simplification and systematization. This makes the unresponsiveness of technology harder to challenge, and ultimately forces the organization to change and adapt to it. Implications for management of practice are outlined.     

Dynamics of Population Ageing in Nepal and the Need for Action

Over the past decades, the problem of ageing has grown steadily in Nepal. The demographic measures obtained from different population censuses of Nepal amply demonstrate this. In this context, the present study attempts to analyze population census 2011 data to assess elderly population across the nation by area types, eco-belts, development regions and by gender perspective through computation of major population ageing indicators for these cross-sectional areas of Nepal. The analysis showed that the indicators like median age, proportion of elderly population, elderly dependency ratio and life expectancy at birth have increased significantly in 2011 census compared to 2001 census stressing the need of appropriate actions for the management, welfare and care of elderly people in Nepal. Even though population ageing is found more evident in urban areas regarding median age and index of ageing, percent elderly population aged 60 and above and elderly dependency are actually higher in rural areas which can be attributed to more out-migration of young people in rural areas. Eco-belt-wise, elderly dependency is found higher in mountain but other ageing indicators are at higher levels in hills. Development region-wise, western region shows relatively more ageing stress compared to other regions except that median age is found highest in the central region. Additionally, two semi-log statistical models that fit well are also built to associate percent elderly populations of Nepal with crude birth rate based upon population censuses of Nepal.     

Repurposing chia seed oil: A versatile novel functional food

Chia seed oil (CSO) has been recently gaining tremendous interest as a functional food. The oil is rich in with polyunsaturated fatty acids (PUFAs), especially, alpha linolenic acid (ALA), linoleic acid (LA), tocopherols, phenolic acids, vitamins, and antioxidants. Extracting CSO through green technologies has been highly efficient, cost-effective, and sustainable, which has also shown to improve its nutritional potential and proved to be eco-friendly than any other traditional or conventional processes. Due to the presence of valuable bioactive metabolites, CSO is proving to be a revolutionary source for food, baking, dairy, pharmaceutical, livestock feed, and cosmetic industries. CSO has been reported to possess antidiabetic, anticancer, anti-inflammatory, antiobesity, antioxidant, antihyperlipidemic, insect-repellent, and skin-healing properties. However, studies on toxicological safety and commercial potency of CSO are limited and therefore the need of the hour is to focus on large-scale molecular mechanistic and clinical studies, which may throw light on the possible translational opportunities of CSO to be utilized to its complete potential. In this review, we have deliberated on the untapped therapeutical possibilities and novel findings about this functional food, its biochemical composition, extraction methods, nutritional profiling, oil stability, and nutraceutical and pharmaceutical applications for its health benefits and ability to counter various diseases.     

Cracking of superheater tube in a captive power plant

ABSTRACT

A steam generator unit in a captive power plant of a heavy water plant reported fish-mouth failure in the secondary super heater bend. The operating pressure of the super heater is 105?kg?cm^?2 and temperature is 485°C. The super heater tubes made of 2¼Cr–1Mo ferritic steel is exposed to steam at a pH of 9.5–10.5 and conductivity less than 2?µS?cm^?1 in the inner surface and at the outer surface exposed to flue gas. It has been operational for last 25 years. Layered deposits were observed at the failed region which were iron oxides. The investigations revealed that outer surface which has flue gas environment showed thinning with oxide scale spallation taking place. The SEM studies showed that there was extensive precipitation of molybdenum sulphide and carbides in the microstructure resulting in preferential oxidation along grain boundaries. The excessive outer thinning of tube resulted in fish-mouth failure of the super heater tube.

This paper is part of a supplementary issue from the 17th Asia-Pacific Corrosion Control Conference (APCCC-17).     

Bulk production of porous TiO2 nanowires by unique solvo-plasma oxidation approach for combating biotic and abiotic water contaminants

Pure, porous titania nanowires (TiO₂-pNW) are produced in bulk amount (~?250 kg/day, reaction time scale?<?1 min) using a unique solvo-plasma oxidation method utilizing microwave plasma with the potential of easy scale up. The prepared nanowire is found to be efficient towards both biotic disinfection and destruction of various abiotic contaminants in wastewaters. In terms of organic contaminants, the TiO₂-pNW is tested for destruction of Rhodamine B (RhB) dye, tetracycline (TC) antibiotic, and diclofenac (DFC) and caffeine (CAF) drugs. In the case of biotic contaminants, the disinfection of E. coli bacteria is demonstrated. In all of the studies, the photocatalytic performance of anatase TiO₂-pNW is compared to that of commercially available P25 nanoparticles (TiO₂-P25), both in the presence and absence of ozone. The excellent photoactivity exhibited by TiO₂-pNW is a result of low recombination rate of electron–hole pair owing to the spatial separation of electrons and holes within the photoexcited nanowires. Moreover, the scavenger experiments and experiments involving ozone reveal that electron transfer and/or presence of dissolved oxygen are the major limiting factors for both porous titania nanowires and P25 spherical powder under UV exposure with photocatalytic activity towards pollutant degradation.

     

Mixing Studies Related to the Cleaning of Molten Aluminium

Molten aluminium is traditionally “cleaned” by a chlorine‐based fluxing gas. This gas also has to provide the motive power for mixing. Recently, mechanical agitation with solid fluxes has been considered as a replacement for environmental reasons. Here, these two methods of mixing are compared using particle image velocimetry (PIV), decolourisation for homogenisation and power measurement for comparison of efficiencies. A geometrically scaled‐down vessel was used, with air to mimic “chlorine” fluxing and with water as the working fluid. At equivalent mean specific energy dissipation rates, _T, maximum velocities are higher and mixing times are shorter with an impeller. This improved performance is achieved with the impeller without causing surface gas entrainment, the latter being detrimental to fluxing.     

Green synthesis,characterisation and biological studies of AgNPs prepared using Shivlingi (Bryonia laciniosa) seed extract

Green synthesis of silver nanoparticles (AgNPs) using Shivlingi (Bryonia laciniosa) seed extract was carried out. Characterisation of synthesised nanoparticles was accomplished through the optical absorption and photoluminescence spectrum, X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The XRD analysis further confirmed the size of nanoparticles ∼15 nm. TEM images revealed homogeneous spherical ∼10 nm Bryonia extract capped AgNPs. The biological studies indicated that both Bryonia seed extract and the nanoparticles lack anti‐microbial activity; however, the nanoparticles had better cytotoxicity and total antioxidant activity. The Lethal concentration (LC)₅₀ value of water extract and the nanoparticles were found to be 1091 and 592 μg/ml, respectively. The lower LC₅₀ of nanoparticles indicates that it is more cytotoxic than the crude extract. The results indicate that the Bryonia seed is safe to be used as a medicine and the formation of their nanoparticle has further enriched the chemical reactivity, energy absorption and biological mobility.Inspec keywords: silver, nanoparticles, nanomedicine, particle size, microorganisms, cellular biophysics, nanofabrication, photoluminescence, X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectra, Raman spectra, antibacterial activity, biochemistryOther keywords: green synthesis, biological studies, Shivlingi seed extraction, Bryonia laciniosa, silver nanoparticles, optical absorption, photoluminescence spectrum, X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, SEM, Fourier transform infrared spectroscopy, Raman spectroscopy, XRD analysis, nanoparticle size, TEM images, homogeneous spherical images, antioxidant activity, water extraction, chemical reactivity, energy absorption, biological mobility, Ag     

基于高斯过程回归和粒子滤波的短期风速预测

建立高斯过程回归和粒子滤波相结合的短期风速预测模型,实现对历史风速序列异常值的在线动态检测与修正。首先,在训练样本集中通过高斯过程回归建立状态空间方程,采用粒子滤波算法对当前量测值进行状态估计,对估计值和量测值的残差进行分析,并根据"3σ"原则判断异常值。其次,修正异常值,并对修正后的风速序列重新建立高斯过程回归预测模型。在进行提前15分钟风速预测时,同样采用粒子滤波算法对最新量测值进行状态估计,实现了异常值在线检测并修正。算例分析结果表明,粒子滤波算法能够有效检测出异常风速值,降低了风速预测误差,提前15分钟风速预测时平均绝对百分比误差和均方根误差分别降至8.92%和0.5826 m/s。     

Experimental Analysis of Pseudospark Sourced Electron Beam

The pseudospark (PS) discharge has been shown to be a promising source of high brightness, high intensity electron beam pulses. The PS discharge sourced electron beam has potential applications in plasma filled microwave sources where normal material cathode cannot be used. Analysis of the electron beam profile has been done experimentally for different applied voltages. The investigation has been carried out at different axial and radial location inside the drift space in argon atmosphere. This paper represents experimentally found axial and radial variation of the beam current inside the drift tube of PS discharge based plasma cathode electron (PCE) gun. With the help of current density estimation the focusing and defocusing point of electron beam in axial direction can be analyzed.