Tank shell stability: refined design schemes Tcepliaev Maxim; Mushchanov Vladimir; Zubenko Anna ...
Magazine of civil engineering,
01/2023, Volume:
119, Issue:
3
Journal Article
Peer reviewed
Open access
In many ways, the reliability of vertical cylindrical tanks is determined by the resistance to buckling of the wall. In the current work, a variant of a detailed design scheme is considered, taking ...into account the presence of a spiral technological staircase for servicing the tank roof. The possibility of using the specified structural element as an external reinforcement to increase stability is analyzed. Finite element models of tanks with volumes of 10..30 thousand m3 were developed. The models took into account the actual distribution of the wind flow for tanks with a circular staircase. Using a multifactorial experiment, an analysis of the stability and stress state of the tank wall was carried out. The variable parameters were: the design solution of the stairs, the dimensions of the tanks and the load. Corresponding graphs and diagrams were constructed. As a result, the design solution and the recommended angle of inclination of the spiral staircase in the range of 30–40° were substantiated. The application of the obtained solutions improved the stability in the annular direction by up to 13 % compared to standard solutions. Wall displacements from wind load are reduced by 14 %, in turn, local stresses in the ladder attachment areas increased by no more than 5 %. In general, the inclusion of spiral staircases significantly increases the stability of the tank wall and can be considered as a good alternative to standard reinforcement methods.
Objective:
The authors carried out a genomewide linkage scan to identify chromosomal regions likely to contain genes that contribute to susceptibility to recurrent early-onset major depressive ...disorder, the form of the disorder with the greatest reported risk to relatives of index cases.
Method:
Microsatellite DNA markers were studied in 656 families with two or more such cases (onset before age 31 in probands and age 41 in other relatives), including 1,494 informative "all possible" affected relative pairs (there were 894 independent affected sibling pairs). Analyses included a primary multipoint allele-sharing analysis (with ALLEGRO) and a secondary logistic regression analysis taking the sex of each relative pair into account (male-male, male-female, female-female).
Results:
Genomewide suggestive evidence for linkage was observed on chromosome 15q25-q26 (at 105.4 centimorgans cM). The authors previously reported genomewide significant linkage in this region in the first 297 families. In the secondary analysis, after empirical genomewide correction for multiple testing, suggestive linkage results were observed on chromosome 17p12 (28.0 cM, excess sharing in male-male and male-female pairs) and on chromosome 8p22-p21.3 (25.1 cM, excess sharing in male-male pairs).
Conclusions:
These regions of chromosomes 15q, 17p, and 8p might contain genes that contribute to susceptibility to major depression and related disorders. Evidence for linkage has been reported independently in the same regions of chromosome 15q for major depression and of chromosome 8p for related personality traits.
The work aims to develop and research a stamp with a differentiated clamp of a rolled stock for cutting by shear. A new stamp design with a differentiated clamp of the rolled stock has been ...developed. In terms of their technical and economic indicators, these stamps meet or exceed the modern samples of similar punch tools. At the same time, in the process of vertical cutting, a constant position of the rolled stock axis is ensured. The transmission of force to the clamp through the rolled stock is excluded. The stamp design ensures its sufficiently high rigidity and relatively small overall dimensions. Based on the analysis of the mathematical model of a stamp with a differentiated clamp, the effective angles of force transmission to the clamp and the cutting of the rolled stock between the stamp parts have been established. The resulting model was used to optimize the angles of force transfer to the clamp, and the cutting rolled stock, respecting the force from the side of a buffer and the minimum required press force. At the same time, the vertical stroke of the moving parts is reduced, the overall dimensions of the stamp are decreased, and the buffer also has a minimum size. To reduce the required force of the press, it is necessary to reduce the value of a frictional slipping coefficient by using antifriction materials on contact surfaces and ensuring good lubrication conditions. The results of the conducted experiments confirm the adequacy of the mathematical model. The value of the required force on the press slide available from experiments is slightly higher than the values obtained by the developed analytical model. The results of the stamp implementation show that: the stamps are efficient and reliable in exploitation; the quality of the cutoff workpieces corresponds to the quality indicators of the workpieces cut on similar modern equipment.
Aim
: to identify inherited and acquired thrombophilia as well as features of pregnancy course in women with abnormal placenta location.
Materials and Methods
. Within the framework of a prospective ...controlled cohort non-randomized, interventional study there was analyzed pregnancy course in 135 women with abnormal placenta location: group I – 42 patients with abnormal placenta location in history; group II – 61 women with placenta previa detected during ongoing pregnancy; group III – 32 patients with placenta previa detected both in ongoing and previous pregnancy. The control group consisted of 120 pregnant women with normal placenta location without a previous complicated obstetric history. All patients underwent clinical examination of pregnancy course assessing fetus intrauterine growth retardation (IUGR) and fetal biophysical profile; inherited and acquired thrombophilia were identified – analyzing circulating antiphospholipid antibodies (APAs) by ELISA, inherited thrombophilia by polymerase chain reaction to identify mutations in genes encoding 5,10methylenetetrahydrofolate reductase (MTHFR), G20210A mutations in prothrombin gene, V Leiden mutation, polymorphismin fibrinogen and plasminogen activator inhibitor 1 (PAI-1) genes.
Results
. Inherited thrombophilia was detected in 101 (74.81 %) pregnant woman with abnormal placenta location: group I – in 31 (73.8 %) patients, group II and group III – in 44 (72.1 %) and 26 (81.3 %) patients, respectively. Inherited forms of thrombophilia were detected in 29 (24.2 %) women from control group. Multigenic forms of thrombophilia peaked in group III (14/43.8 %), followed by group I (16/38.1 %) and group II (23/37.7 %). In the control group, multigenic thrombophilia was detected in 16 (13.3 %) women. Selective inherited thrombophilia and АРАs circulation were detected in 30 (22.22 %) women with abnormal placenta location: group I – in 8 (19.0 %) patients, group II – in 13 (21.3 %), and group III – in 9 (28.1 %) cases. In the control group, there were only 8 (6.7 %) such patients. Patients with IUGR signs were identified in all study groups: 4 (9.52 %) in group I, 6 (9.84 %) in group II, 6 (18.75 %) in group III as well as in control group in 6 (6.67 %) women.
Conclusion
. Pregnancy management in patients with thrombophilia and placental abnormalities should be accompanied by an proper fetal assessment (biophysical profile) and, in some cases, anticoagulant or antiplatelet therapy. However, insufficient number of cases requires to conduct further investigations to assess a relation between thrombophilia, placenta previa and a risk of obstetric complications particularly IUGR.
Bousman and Muller comment on the viewpoints on pharmacogenetic tests for psychiatric treatment boldly which states that "the available evidence suggests Pgen pharmacogenetic tests will not ...contribute much to care." They believe that the foundation from which the authors based their statement is incomplete and potentially misleading.
In this work we presented a synthesis and investigation of relative acyclic and macrocyclic polyamines with picolinate pendant arms as potential chelators for copper radiopharmaceuticals. It has been ...shown that linear chelators lacking bisamide moiety are much more basic and form complexes with higher stability constants compared to macrocyclic ones. Both types of ligands possess many donor sites due to picolinate groups enabling formation of polynuclear complexes in the solution and solid state. According to crystal structures metal cations coordinates with studied ligands through the binding with aminogroups and picolinates donor atoms, while terminal aminogroups of acyclic ligands do not take part in the complex formation. Tripicolinate azacrown ligand coordinates cations outside the macrocyclic cavity in non‐equivalent positions. However this out‐cage location as well as a moderate logK value do not induce fast release of cation from this complex in the challenging medium of serum proteins.
Picolinate ligands originated from one precursor with different rigidity were synthesized and compared in terms of complexation ability towards Copper cations as potential parts of Copper‐64 radiopharmaceuticals. It was shown that both structure and basicity play important roles in the binding of cation. Wherein azacrown polyamine provides stable chelation even possessing lower logβ and coordinating cation in the out‐cage manner.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Copper(
ii
) coordination compounds with the condensation products of diacetylmonoxime and 2-hydrazino-4,6-dimethylpirimidine (H
2
L) with the compositions of Cu(H
2
L)Br
2
·H
2
O (
I
) and Cu(H
2
...L)Cl
2
(
II
) were synthesized. The molecular structures of the compounds were established with the help of a single-crystal X-ray diffraction study. In the case of (
I
), H
2
O molecules facilitated the formation of an infinite intermolecular hydrogen bonding (HB) network, leading to ferromagnetic-type exchange interactions between the copper(
ii
) ions of mononuclear coordination units and antiferromagnetic molecular field (2
J
= +5.53 cm
−1
, z
J
′ = −0.53 cm
−1
). At the same time in (
II
) -(O-H)
oxime
Cl centrosymmetric hydrogen-bonded dimers were formed from mononuclear coordination units, resulting in the presence of antiferromagnetic exchange interactions between the Cu(
ii
) centres and molecular field interactions of the ferromagnetic type (2
J
= −2.21 cm
−1
, z
J
′ = +0.63 cm
−1
). DFT-BS calculations were employed to clarify the nature of the pairwise exchange interactions in the crystals of (
I
) and (
II
), and to calculate the exchange interaction parameters for several supramolecular dimers, modelling the possible superexchange pathways in the crystalline structures of
I
and
II
. In both compounds, intermolecular HBs gave rise to weak magnetic exchange interactions of both the ferro- and antiferromagnetic types.
A nontrivial case of a combination of ferro- and antiferromagnetic exchange interactions in mononuclear copper(
ii
) complexes, determined by HB networks, is reported.
Copper-based radiopharmaceuticals are of high interest these days owing to the decay properties of copper radioisotopes. In contrast, labeled zinc compounds have been less studied for applications in ...nuclear medicine. In this study, the stability of labeled zinc and copper complexes with two azacrown ether ligands was investigated and compared. Then, the in vitro and in vivo stability of the studied zinc complexes was demonstrated, with the complexes showing promise for biomedical applications. In contrast, analogous copper complexes quickly dissociated in the presence of serum proteins. Furthermore, a simple method for the production of radiochemically pure 65Zn was proposed, and the opportunity for its use as a surrogate radionuclide for research into potential zinc-containing radiopharmaceuticals was demonstrated.
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•Cu(II) complexes of N-{2-(2-diethylaminoalkylimino)methylphenyl}-4-tosylsulfonamide were obtained.•Copper ions have either a distorted square planar or square pyramidal ...environment.•The obtained copper complexes exhibit high protistocidal activity.
A series of copper(II) complexes with new Schiff bases, namely N-{2-(2-diethylamino(alkyl)imino)-methyl-phenyl}-4-methylbenzenesulfonamide alkyl = ethyl (HL1) or propyl (HL2), were synthesized using copper acetate or chloride and characterized by elemental analysis, IR and X-ray absorption spectroscopy, and single-crystal X-ray diffraction. The coordination geometry around the Cu(II) ion in Cu(L1)2 and Cu(L2)2 was studied by X-ray absorption spectroscopy. The crystal structures of copper(II) complexes with L1 ligand synthesized from copper chloride and copper acetate with addition of sodium azide have been determined by X-ray diffraction. The azomethines and all copper(II) complexes have been screened for their antibacterial, protistocidal, and fungistatic activities against Penicillium italicum, Colpoda steinii, Escherichia coli 078, and Staphylococcus aureus P-209.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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