A Numerical model of exchange chromatography through 3‐D lattice structures

Rapid progress in the development of additive manufacturing technologies is opening new opportunities to fabricate structures that control mass transport in three dimensions across a broad range of length scales. We describe a structure that can be fabricated by newly available commercial 3‐D printers. It contains an array of regular three‐dimensional flow paths that are in intimate contact with a solid phase, and thoroughly shuffle material among the paths. We implement a chemically reacting flow model to study its behavior as an exchange chromatography column, and compare it to an array of 1‐D flow paths that resemble more traditional honeycomb monoliths. A reaction front moves through the columns and then elutes. The front is sharper at all flow rates for the structure with three‐dimensional flow paths, and this structure is more robust to channel width defects than the 1‐D array. © 2018 American Institute of Chemical Engineers AIChE J, 64: 1874–1884, 2018     

System identification and uncertainty modeling of an electromechanical actuator

The electromechanical actuator (EMA) is of interest for applications which require easy control and high dynamics. This article deals with the analytical and uncertainties modeling, experimental identification, and model validation of a position control EMA and its “motor with harmonic drive” subsystem. They are identified and modeled as linear systems with parametric uncertainty using their experimental input–output data. The captured data, related to several working points under different conditions, were used for model estimation and validation purposes. Furthermore, the discrepancies between the linear model and the actual system, due to nonlinearities, were estimated as multiplicative uncertainty. The model is validated on the base of reproducing system behavior within acceptable bounds with minimum error. Validation results proved the derived model viability to be used for designing a robust EMA system to perform within acceptable bandwidth.     

An online prognostics-based health management strategy for fuel cell hybrid electric vehicles

As the energy transformation in the transportation sector is taking place driven by the development of fuel cell technologies, fuel cell hybrid electric vehicles become promising solutions owing to their long driving duration and zero emissions. However, the unsatisfied lifespan of fuel cells is an inevitable obstacle for their massive commercialization. This paper aims to propose an online adaptive prognostics-based health management strategy for fuel cell hybrid electric vehicles, which can improve the durability of the fuel cell thanks to online health monitoring. Here, particle filtering method is adapted for online fuel cell prognostics and the uncertainty of the predicted results is calculated based on the distribution of particles. A health management strategy is developed based on prognostics and a decision-making process is designed by considering the prognostics uncertainty through a decision fusion method. The obtained results show that the developed strategy has effectively improved the durability of the on-board fuel cell by up to 95.4%. Moreover, a sensitivity analysis of the prognostics occurrence frequency and probability calculation has also been conducted in this paper.     

Effect of stove asymmetric radiation field on thermal comfort using a multisegmented bioheat model

The multinode multisegment bioheat model of Salloum et al. [Salloum M, Ghaddar N, Ghali K. A new transient bio-heat model of the human body. In: Proceedings of the ASME 2005 summer heat transfer conference, 17–22 July 2005, San Francisco, Paper no. HT2005-72303] is integrated with a space heat model to study human thermal response when subjected to radiant asymmetry in stove-heated domestic spaces in Lebanon. For any given person position, the overall comfort level is based on Frank et al. model correlations [Frank SM, Srinivasa NR, Bulcao CF, Goldstein DS. Relative contribution of core and cutaneous temperatures to thermal comfort and autonomic responses in humans. Journal of Applied physiology 1999;86(5):1588–93]. The assessment of local comfort level is based on the maximum deviation of the clothed segments skin temperature from the mean skin temperature and its relation to the radiant temperature asymmetry.

Experiments were run on human subjects at steady-state conditions to measure the variation of the skin temperature at different locations of the human body segments while standing in an asymmetric thermal radiation field generated by a stove-heating unit. The experiments were conducted to validate the applicability of the bioheat model in predicting skin temperature in asymmetric conditions. The measured skin temperature of various body segments and the radiative asymmetry agreed within ±5% of values predicted by the bioheat model [Salloum M, Ghaddar N, Ghali K. A new transient bio-heat model of the human body. In: Proceedings of the ASME 2005 summer heat transfer conference, 17–22 July 2005, San Francisco, Paper no. HT2005-72303].

The space heat model and the bioheat model are applied to a case study to predict both overall thermal comfort and local thermal discomfort in a typical radiant heat space at different standing positions of the person. Strong thermal discomfort exists within the vicinity of the stove high-temperature surface. The local discomfort is considered at values of maximum SD>1.1 °C derived from consideration of Fanger et al. [Fanger PO, Ipsen BM, Langkilde G, Olesen BW. Comfort limits for asymmetric thermal radiation. Energy and Buildings 1985;8(3):225–36] data of comfort limits and skin temperature measurements for asymmetric thermal radiation.     

Differential amygdala activation in schizophrenia during sadness

Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) is the etiologic agent of paratuberculosis (Johne's disease), a chronic granulomatous enteritis in ruminants. Currently, there is a need for improved diagnostic tests because of the lack of methods for accurate, rapid and reliable detection of M. paratuberculosis infection. A M. paratuberculosis gene (hspX) was cloned, sequenced, and a 30 bp species-specific oligonucleotide was synthesized. As an internal control to identify mycobacterial strains, a 33 bp Mycobacterium genus-specific oligonucleotide was synthesized based on the conserved 5' terminus of the mycobacterial recA gene. Dioligonucleotide hybridization (dOH) analysis identified 28/28 (100%) mycobacterial strains and specifically identified 14/14 (100%) reference (ATCC 19698), bovine, ovine and human isolates of M. paratuberculosis. The M. paratuberculosis-specific oligonucleotide distinguished M. paratuberculosis isolates from related mycobacteria, including all closely related members of the Mycobacterium avium complex (MAC) tested in this study. The members of MAC tested in this study included Mycobacterium avium subspecies avium (M. paratuberculosis, Mycobacterium avium subspecies silvaticum (M. silvaticum) and Mycobacterium intracellulare strains. Hybridization was not observed with DNA extracted from a selected group of other bacterial pathogens. The experiments indicate that the dOH analysis is a useful diagnostic tool to detect mycobacterial infection, specifically M. paratuberculosis. The dOH method could be a good alternative to existing assays and will be adapted for specific identification of M. paratuberculosis from faecal samples, mixed bacteriologic cultures, tissue specimens and whole blood.     

Increasing treatment adherence among outpatients with depression and cocaine dependence: results of a pilot study

OBJECTIVE: This pilot study examined the effect of a modified motivational therapy intervention on outpatient treatment adherence and completion for patients with comorbid depressive disorder and cocaine dependence. METHOD: Depressed cocaine patients, stabilized with antidepressant medications on an inpatient psychiatric unit, were consecutively assigned on discharge to motivational therapy (N = 11) or treatment-as-usual (N = 12) during the first month of outpatient care. Patients were compared on treatment adherence and completion and on 1-year rehospitalization rates. RESULTS: Motivational therapy patients attended significantly more treatment sessions during month 1, completed 30 and 90 days of outpatient care at higher rates, and experienced fewer psychiatric rehospitalizations and days in the hospital during the first year from entry into outpatient treatment. CONCLUSIONS: An outpatient program combining individual and group motivational therapy sessions holds promise for improving treatment adherence and completion among depressed patients with cocaine dependence.     

The Effect of Strain Rate and Temperature on the Mechanical Behavior of Al/Fe Interface Under Compressive Loading

Metallurgical and Materials Transactions A - Molecular dynamics (MD) is employed to simulate the mechanical response of Al/Fe interface under compression at extreme conditions of seven temperatures...     

Moisture buffering capacity of novel solar‐regenerated rotating hygroscopic curtain system

This study proposes a rotating hygroscopic curtain to control indoor relative humidity. The curtain continuously exchanges heat and moisture with the two environments: the internal space where the curtain undergoes absorption and the space between curtain and glass window where it undergoes desorption releasing the collected space moisture to the exhausted airstream. In this work, a theoretical model is developed for the curtain system with an integrated indoor space modal to study the rotating hygroscopic curtain feasibility in performing indoor dehumidification. An experimental setup was built inside climatic chambers for validating the model predictions of room air temperature and moisture removal rate. Experimental data of the curtain‐absorbed moisture and the chamber indoor humidity showed good comparison with the model simulation values. A case study was evaluated to predict the effectiveness of a highly moisture‐absorbing cotton curtain used inside an office in Beirut City having an area of 42 m². At a given load, the hygroscopic curtain maintained an average relative humidity of about 65.7% when rotating continuously at a speed of 1.5 rpm compared with a value of 71.1% when the curtain was stationary. Copyright © 2015 John Wiley & Sons, Ltd.     

Fast optimal diagnosis procedures for k-out-of-n:G systems

A k-out-of-n:G system consists of a set of components, where each component is either faulty or fault-free. The system is working if at least k components are fault-free. The problem of finding an optimal diagnosis procedure for a given k-out-of-n:G system has been considered in several research fields including medical diagnosis, redundant-system testing, and searching data-files. A polynomial-time algorithm for this problem was presented first by Salloum, and later by Salloum and Breuer, and independently by Ben-Dov. This paper implements the Salloum-Breuer-Ben-Dov algorithm, leading to an optimal diagnosis procedure that can determine the state of any given system in O(n·log(n)) time complexity and O(n) space complexity. The efficiency is achieved by using a generalized radix sorting procedure that uses a heap data structure. For some k-out-of-n:G systems, including those with equal testing costs for all components, the components along the leftmost and rightmost paths in the optimal diagnostic tree uniquely determine the other components in the tree. This property is used to devise a faster optimal diagnosis procedure than the one for the general k-out-of-n:G system. With regard to complexity, these procedures are the best solutions for the problem under consideration. This conjecture is supported by the fact that all these procedures require a sorting operation which has O(n·log(n)) as a lower bound on its time complexity     

Burkitt's lymphoma-leukemia in patients treated for Hodgkin's disease

We reviewed all reported cases of Burkitt's lymphoma and/or Burkitt's leukemia (BLL) occurring following therapy for Hodgkin's disease. In addition to the case described in this report, a total of 19 patients have been previously reported. The male/female ratio was 3.75. Treatment for Hodgkin's disease included chemotherapy combined with radiation therapy in 15 patients, chemotherapy in 3 patients, and radiation therapy alone in 1 patient. Median interval between Hodgkin's disease and the diagnosis of BLL was 97 months. Patient characteristics are similar to those with de novo BLL. Bone marrow, abdomen, central nervous system, as well as extranodal organs were commonly involved. Typical cytogenetic translocations seen in patients with primary BLL were found in 6 patients, but 5 of these patients had additional cytogenetic abnormalities. Only 2 patients achieved complete remission after chemotherapy. The mechanism for the development of BLL after treatment for Hodgkin's disease is unknown. Although the majority of cases have been seen in patients treated with combined-modality therapy, the role of previous therapy in causing this complication cannot be assessed in this study.