Fouling Mitigation Using Helixchanger Heat Exchangers

One of the major indeterminates in the design as well as operation of heat exchangers is the rate of fouling a select heat exchanger geometry would exhibit over the operation cycles. Gradual deterioration of heat exchanger performance due to the accumulation of fouling film on the heat transfer surface is often accounted for in the form of a fouling resistance, or commonly known as the fouling factor, while determining the heat transfer surface required for a specific heat duty. More often, the fouling mechanism responsible for the deterioration of heat exchanger performance is flow-velocity dependent. Maldistribution of flow, wakes and eddies caused by poor heat exchanger geometry can have detrimental effect on heat exchanger performance and reliability. Helixchanger heat exchangers have demonstrated significant improvements in the fouling behavior of heat exchangers in operation. In a Helixchanger heat exchanger, the quadrant shaped shellside baffle plates are arranged at an angle to the tube axis creating a helical flow pattern on the shellside. Uniform velocities and near plug flow conditions achieved in a Helixchanger heat exchanger, provide low fouling characteristics, offering longer heat exchanger run-lengths between scheduled cleaning of tube bundles. This article demonstrates the Helixchanger heat exchanger option in reducing the velocity-dependent fouling in heat exchangers

Analisis Hasil Pemeriksaan Spesimen Darah Penderita Demam Berdarah Dengue di Jakarta Tahun 1988

Dengue Haemorrhagic Fever is an endemic and important public health disease in Indonesia. Surveillance of hospitalized case usually reported 5.000 cases annually but 10.000 cases could be reported during an outbreak period. The case fatality rate had been decreasing to 4% at present. Studies to analyse the risk factors of an area, pathophysiology of shock or bleeding, prevention, eradication and surveillance were still needed. The important Dengue Haemorrhagic Fever factors were analysed in this tudy based on the 1756 specimens tested in the Communicable Disease Research Center during the period from January1988 to Desember 1988, sent by most of the hospitals in Jakarta. The overall difference between male and female was not significant, although on January, July, September and Desember 1988 females were almost 2 times higher then males.Theoverall difference of children and adult groups were also not significant, although on February, March, November and Decem­ber 1988 adults were higher 2-5 times then children. This findings were not usual. The antibody response titers during acute and convalescence period of illness was lower among chil­dren. These findings were not usual. The antibody response titers during acute and convalescence period of illness was lower among chil­dren then adults, although it was still lower then in Thailand

Quantum simulation of spin ordering with nuclear spins in a solid state lattice

An experiment demonstrating the quantum simulation of a spin-lattice Hamiltonian is proposed. Dipolar interactions between nuclear spins in a solid state lattice can be modulated by rapid radio-frequency pulses. In this way, the effective Hamiltonian of the system can be brought to the form of an antiferromagnetic Heisenberg model with long range interactions. Using a semiconducting material with strong optical properties such as InP, cooling of nuclear spins could be achieved by means of optical pumping. An additional cooling stage is provided by adiabatic demagnetization in the rotating frame (ADRF) down to a nuclear spin temperature at which we expect a phase transition from a paramagnetic to antiferromagnetic phase. This phase transition could be observed by probing the magnetic susceptibility of the spin-lattice. Our calculations suggest that employing current optical pumping technology, observation of this phase transition is within experimental reach.Comment: 11 pages, 3 figues; Published versio

Towards the development of an Inter-Cultural Scale to Measure Trust in Automation

Trust is conceived as an attitude leading to intentions resulting in user actions involving automation. It is generally believed that trust is dynamic and that a user’s prior experience with automation affects future behavior indirectly through causing changes in trust. Additionally, individual differences and cultural factors have been frequently cited as the contributors to influencing trust beliefs about using and monitoring automation. The presented research focuses on modeling human’s trust when interacting with automated systems across cultures. The initial trust assessment instrument, comprising 110 items along with 2 perceptions (general vs. specific use of automation), has been empirically validated. Detailed results comparing items and dimensionality with our new pooled measure will be presented

The Effects of Yoga on Balance, Strength, Flexibility, and Mindfulness in Typical Children Ages 4-9 Years

Yoga improves a variety of impairments in typical pediatric populations: cardiovascular, neuromuscular, musculoskeletal, and pulmonary conditions, balance, strength, and flexibility. Yoga improves mindfulness in adult populations, and emerging evidence shows a similar effect among pediatric populations.https://ecommons.udayton.edu/dpt_symposium/1024/thumbnail.jp

Autophagy Is a Defense Mechanism Inhibiting BCG and Mycobacterium tuberculosis Survival in Infected Macrophages

AbstractMycobacterium tuberculosis is an intracellular pathogen persisting within phagosomes through interference with phagolysosome biogenesis. Here we show that stimulation of autophagic pathways in macrophages causes mycobacterial phagosomes to mature into phagolysosomes. Physiological induction of autophagy or its pharmacological stimulation by rapamycin resulted in mycobacterial phagosome colocalization with the autophagy effector LC3, an elongation factor in autophagosome formation. Autophagy stimulation increased phagosomal colocalization with Beclin-1, a subunit of the phosphatidylinositol 3-kinase hVPS34, necessary for autophagy and a target for mycobacterial phagosome maturation arrest. Induction of autophagy suppressed intracellular survival of mycobacteria. IFN-γ induced autophagy in macrophages, and so did transfection with LRG-47, an effector of IFN-γ required for antimycobacterial action. These findings demonstrate that autophagic pathways can overcome the trafficking block imposed by M. tuberculosis. Autophagy, which is a hormonally, developmentally, and, as shown here, immunologically regulated process, represents an underappreciated innate defense mechanism for control of intracellular pathogens

Remote Actuation of Magnetic Nanoparticles For Cancer Cell Selective Treatment Through Cytoskeletal Disruption

Motion of micron and sub-micron size magnetic particles in alternating magnetic fields can activate mechanosensitive cellular functions or physically destruct cancer cells. However, such effects are usually observed with relatively large magnetic particles (>250 nm) that would be difficult if at all possible to deliver to remote sites in the body to treat disease. Here we show a completely new mechanism of selective toxicity of superparamagnetic nanoparticles (SMNP) of 7 to 8 nm in diameter to cancer cells. These particles are coated by block copolymers, which facilitates their entry into the cells and clustering in the lysosomes, where they are then magneto-mechanically actuated by remotely applied alternating current (AC) magnetic fields of very low frequency (50 Hz). Such fields and treatments are safe for surrounding tissues but produce cytoskeletal disruption and subsequent death of cancer cells while leaving healthy cells intact

Task-related enhancement in corticomotor excitability during haptic sensing with the contra- or ipsilateral hand in young and senior adults

<p>Abstract</p> <p>Background</p> <p>Haptic sensing with the fingers represents a unique class of manipulative actions, engaging motor, somatosensory and associative areas of the cortex while requiring only minimal forces and relatively simple movement patterns. Using transcranial magnetic stimulation (TMS), we investigated task-related changes in motor evoked potential (MEP) amplitude associated with unimanual haptic sensing in two related experiments. In Experiment I, we contrasted changes in the excitability of the hemisphere controlling the task hand in young and old adults under two trial conditions, i.e. when participants either touched a fine grating (<it>smooth trials</it>) or touched a coarse grating to detect its groove orientation (<it>grating trials</it>). In Experiment II, the same contrast between tasks was performed but with TMS applied over the hemisphere controlling the resting hand, while also addressing hemispheric (right vs. left) and age differences.</p> <p>Results</p> <p>In Experiment I, a main effect of <it>trial type </it>on MEP amplitude was detected (p = 0.001), MEPs in the task hand being ~50% larger during grating than smooth trials. No interaction with age was detected. Similar results were found for Experiment II, <it>trial type </it>having a large effect on MEP amplitude in the resting hand (p < 0.001) owing to selective increase in MEP size (~2.6 times greater) for grating trials. No interactions with age or side (right vs. left) were detected.</p> <p>Conclusions</p> <p>Collectively, these results indicate that adding a haptic component to a simple unilateral finger action can elicit robust corticomotor facilitation not only in the working hemisphere but also in the opposite hemisphere. The fact that this facilitation seems well preserved with age, when task difficulty is adjusted, has some potential clinical implications.</p

Differential modulation of corticospinal excitability during haptic sensing of 2-D patterns vs. textures

<p>Abstract</p> <p>Background</p> <p>Recently, we showed a selective enhancement in corticospinal excitability when participants actively discriminated raised 2-D symbols with the index finger. This extra-facilitation likely reflected activation in the premotor and dorsal prefrontal cortices modulating motor cortical activity during attention to haptic sensing. However, this parieto-frontal network appears to be finely modulated depending upon whether haptic sensing is directed towards material or geometric properties. To examine this issue, we contrasted changes in corticospinal excitability when young adults (n = 18) were engaged in either a roughness discrimination on two gratings with different spatial periods, or a 2-D pattern discrimination of the relative offset in the alignment of a row of small circles in the upward or downward direction.</p> <p>Results</p> <p>A significant effect of task conditions was detected on motor evoked potential amplitudes, reflecting the observation that corticospinal facilitation was, on average, ~18% greater in the pattern discrimination than in the roughness discrimination.</p> <p>Conclusions</p> <p>This differential modulation of corticospinal excitability during haptic sensing of 2-D patterns vs. roughness is consistent with the existence of preferred activation of a visuo-haptic cortical dorsal stream network including frontal motor areas during spatial vs. intensive processing of surface properties in the haptic system.</p

The complex TIE between macrophages and angiogenesis

Macrophages are primarily known as phagocytic immune cells, but they also play a role in diverse processes, such as morphogenesis, homeostasis and regeneration. In this review, we discuss the influence of macrophages on angiogenesis, the process of new blood vessel formation from the pre-existing vasculature. Macrophages play crucial roles at each step of the angiogenic cascade, starting from new blood vessel sprouting to the remodelling of the vascular plexus and vessel maturation. Macrophages form promising targets for both pro- and anti-angiogenic treatments. However, to target macrophages, we will first need to understand the mechanisms that control the functional plasticity of macrophages during each of the steps of the angiogenic cascade. Here, we review recent insights in this topic. Special attention will be given to the TIE2-expressing macrophage (TEM), which is a subtype of highly angiogenic macrophages that is able to influence angiogenesis via the angiopoietin-TIE pathway