[NH3(CH2)2NH3][Co(SO4)2(H2O)4]: Chemical preparation, crystal structure, thermal decomposition and magnetic properties

Cobalt ethylenediammonium bis(sulfate) tetrahydrate, [NH₃(CH₂)₂NH₃][Co(SO₄)₂(H₂O)₄], has been synthesised by slow evaporation at room temperature. It crystallises in the triclinic system, space group , with the unit cell parameters: a = 6.8033(2), b = 7.0705(2), c = 7.2192(3) Å, α = 74.909(2)°, β = 72.291(2)°, γ = 79.167(2)°, Z = 1 and V = 317.16(2) Å³. The Co(II) atom is octahedrally coordinated by four water molecules and two sulfate tetrahedra leading to trimeric units [Co(SO₄)₂(H₂O)₄]. These units are linked to each other and to the ethylenediammonium cations through OW-H…O and N-H…O hydrogen bonds, respectively. The zero-dimensional structure is described as an alternation between cationic and anionic layers along the crystallographic b-axis. The dehydration of the precursor proceeds through three stages leading to crystalline intermediary hydrate phases and an anhydrous compound. The magnetic measurements show that the title compound is predominantly paramagnetic with weak antiferromagnetic interactions.     

Surface roughness and cutting forces modeling for optimization of machining condition in finish hard turning of AISI 52100 steel

An experimental investigation was conducted to analyze the effect of cutting parameters (cutting speed, feed rate and depth of cut) and workpiece hardness on surface roughness and cutting force components. The finish hard turning of AISI 52100 steel with coated Al₂O₃ + TiC mixed ceramic cutting tools was studied. The planning of experiment were based on Taguchi’s L₂₇ orthogonal array. The response table and analysis of variance (ANOVA) have allowed to check the validity of linear regression model and to determine the significant parameters affecting the surface roughness and cutting forces. The statistical analysis reveals that the feed rate, workpiece hardness and cutting speed have significant effects in reducing the surface roughness; whereas the depth of cut, workpiece hardness and feed rate are observed to have a statistically significant impact on the cutting force components than the cutting speed. Consequently, empirical models were developed to correlate the cutting parameters and workpiece hardness with surface roughness and cutting forces. The optimum machining conditions to produce the lowest surface roughness with minimal cutting force components under these experimental conditions were searched using desirability function approach for multiple response factors optimization. Finally, confirmation experiments were performed to verify the pertinence of the developed empirical models.     

A case-control study on the association of idiopathic recurrent pregnancy loss with autoantibodies against beta2-glycoprotein I and annexin V

Whereas antiphospholipid antibodies (aPL) are associated with thrombotic events and recurrent spontaneous abortion (RSA), the contribution of anti-beta2 glycoprotein 1 (beta2GP1) and anti-annexin V antibodies as risk factors for RSA remain poorly understood. We investigated anti-beta2-GPI and anti-annexin V IgM and IgG antibodies as potential risk factors for RSA in 200 women with more than three consecutive idiopathic RSA, and 200 age-matched, healthy, parous women. Pearson's chi squared test analysis showed that while anti-beta2-GPI IgG (P = 0.416) and IgM (P = 0.72) were comparable between patients and controls, elevated anti-annexin V IgG (P = 0.006), but not IgM (P = 0.084), was more pronounced in patients. Higher frequencies of elevated IgG-only (P = 0.005), but not IgM-only (P = 1.000; OR = 6.66), anti-annexin V antibodies were noted among patients. Multinomial regression analysis showed that body-mass index (overweight and obesity; P = 0.008), education status (P < 0.001) and anti-beta2-GPI IgM (P = 0.033), but not IgG (P = 0.723), were associated with early abortion, while anti-beta2-GPI IgG (P = 0.030) and anti-annexin V IgG (P = 0.004) were associated with late RSA. For combined early-late RSA, the only variable selected was education status (P < 0.001), and neither anti-annexin V nor anti-beta2-GPI IgM and IgG was associated with early-late RSA. Accordingly, anti-annexin V and anti-beta2-GPI should be regarded as independent risk markers of RSA.     

Characterization and assessment of Al Ruwais refinery wastewater

An extensive bulk parameters and component-based analysis was carried out for Al Ruwais refinery wastewater during the period of June 2002-June 2003. The program included identification of major process and utilities wastewater streams and quantification of these streams relative to the total wastewater generated from all refinery processes. In addition to the high biochemical oxygen demand (BOD) and chemical oxygen demand (COD) reported levels, the analysis showed high concentrations of polyaromatic hydrocarbons (PAHs) and phenolic compounds in the major wastewater streams. Polychlorinated biphenyls (PCBs) were also detected in few streams. The caustic water was found to have the highest levels of the pollutants mentioned above. Dilution of the wastewater with process cooling water serves as the main treatment approach applied to the effluent wastewater before disposal into the sea. Primary as well as secondary treatment units are thought to be essential and strongly recommended to reduce the pollutants to levels below the United Arab Emirates (UAE) standards for marine discharge.     

Receptor-ligand-based specific cell adhesion on solid surfaces: hippocampal neuronal cells on bilinker functionalized glass

Cell adhesion through binding between specific cell membrane receptors and corresponding cell-adhesion-molecule (CAM)-coated solid surfaces is examined. The morphology of surfaces at various modification steps leading to functionalization with cell-binding CAMs is characterized. In one week neuron cultures, enhanced growth on surfaces modified with neuron-binding versus astrocyte-binding CAMs is observed. However, nonspecific adhesion on a poly-D-lysine-coated positive control surface is found to be even higher. Potential reasons and further studies needed are discussed.     

Exploring video content structure for hierarchical summarization

In this paper, we propose a hierarchical video summarization strategy that explores video content structure to provide the users with a scalable, multilevel video summary. First, video-shot- segmentation and keyframe-extraction algorithms are applied to parse video sequences into physical shots and discrete keyframes. Next, an affinity (self-correlation) matrix is constructed to merge visually similar shots into clusters (supergroups). Since video shots with high similarities do not necessarily imply that they belong to the same story unit, temporal information is adopted by merging temporally adjacent shots (within a specified distance) from the supergroup into each video group. A video-scene-detection algorithm is thus proposed to merge temporally or spatially correlated video groups into scenario units. This is followed by a scene-clustering algorithm that eliminates visual redundancy among the units. A hierarchical video content structure with increasing granularity is constructed from the clustered scenes, video scenes, and video groups to keyframes. Finally, we introduce a hierarchical video summarization scheme by executing various approaches at different levels of the video content hierarchy to statically or dynamically construct the video summary. Extensive experiments based on real-world videos have been performed to validate the effectiveness of the proposed approach.Published online: 15 September 2004 Corespondence to: Xingquan ZhuThis research has been supported by the NSF under grants 9972883-EIA, 9974255-IIS, 9983248-EIA, and 0209120-IIS, a grant from the state of Indiana 21^th Century Fund, and by the U.S. Army Research Laboratory and the U.S. Army Research Office under grant DAAD19-02-1-0178.     

An Immutable Framework for Smart Healthcare Using Blockchain Technology

The advancements in sensing technologies, information processing, and communication schemes have revolutionized the healthcare sector. Electronic Healthcare Records (EHR) facilitate the patients, doctors, hospitals, and other stakeholders to maintain valuable data and medical records. The traditional EHRs are based on cloud-based architectures and are susceptible to multiple cyberattacks. A single attempt of a successful Denial of Service (DoS) attack can compromise the complete healthcare system. This article introduces a secure and immutable blockchain-based framework for the Internet of Medical Things (IoMT) to address the stated challenges. The proposed architecture is on the idea of a lightweight private blockchain-based network that facilitates the users and hospitals to perform multiple healthcare-related operations in a secure and trustworthy manner. The efficacy of the proposed framework is evaluated in the context of service execution time and throughput. The experimental outcomes indicate that the proposed design attained lower service execution time and higher throughput under different control parameters.