Методика расчёта одно- и двухярусных микрощелевых теплообменников

Наведено методику розрахунку потужності мідного і алюмінієвого теплообмінника з мікроканалами різних розмірів. Розрахунок базується на визначенні ефективності оребрення.Power was calculated for copper and aluminum heat exchanger with microchannels of different dimensions on all height of heat exchanger. The calculation is based on the calculation of the fins.Приведена методика расчёта мощности медного и алюминиевого теплообменника с микроканалами разных размеров. Расчёт основывается на определении эффективности оребрения

Radiomorphological Parameters of the Foot Bones During the Talus Fracture Treatment Using the Ilizarov Apparatus

Background: Talus fractures are one of the most dangerous injuries leading to serious consequences. Quite a lot of treatment methods have been proposed, but the use of the Ilizarov apparatus is relatively rare.   Objective: To justify the use of the Ilizarov apparatus in the talus fracture treatment by studying radiomorphological parameters of the foot bones at different stages of follow-up.   Methods: We used radiography and multislice computed tomography (MSCT) in 25 patients treated for talus injuries by the Ilizarov apparatus to study radiographic and radiomorphological features of the foot bones at different stages of follow-up. We analyzed normal parameters of the foot bones forming the ankle joint in 15 patients.   Results and discussion: Dynamics of talus radiomorphology during its fracture or fracture-dislocation are characterized by a gradual increase in the bone density at the union site. The local density of the talus at the fracture site gradually increased and exceeded 500 HU in 6 months. The organotypic adjustment at the union site did not end by this time, given the architecture of the talus and the biomechanics of the foot. We observed a decrease in the total densities of the talus and calcaneus during fixation by the Ilizarov apparatus and their gradual return to normal values after removal of the apparatus.   Conclusions: Talus fracture treatment by transosseous osteosynthesis using the Ilizarov apparatus makes it possible to get immediate good results, especially using a configuration with hinges allowing for early mobilization of the ankle joint and loading in the early stages of treatment

Mineral and bone metabolism in patients with idiopathic scoliosis depending on the magnitude of the deformity

Objective: Analysis of the results of the study of mineral metabolism and bone formation markers in patients with idiopathic scoliosis, depending on the magnitude of the deformity.Material and methods: Based on the retrospective single‑center study in 30 patients diagnosed with scoliosis the preoperative parameters of calcium metabolism (total and ionized calcium, parathyroid hormone, 24‑hour urine calcium), phosphorus, bone formation markers (alkaline phosphatase, osteocalcin, P1NP in the blood), deoxypyridinoline in morning urine, blood levels of 25(OH)D have been analyzed. The patients were divided into 3 groups: with a deformity of 25–40 ° (group 1), 40–60 ° (group 2) and 60–80 ° (group 3) (n = 30). The mean age in all groups was 18.5 ± 4.7.Results: In patients with idiopathic scoliosis, alkaline phosphatase and P1NP significantly exceeded normal values in the first group, which indicated a more high‑turnover type of bone remodeling with a deficient level of 25(OH)D. A higher excretion of deoxypyridinoline and a decrease in phosphorus in blood in patients with a deformity of 60–80 ° suggest a violation of the ratio of the processes of synthesis and resorption in bone tissue.Conclusion: The study of mineral metabolism and all the main markers of bone formation made it possible to obtain a more complete picture of the state of metabolic processes in bone tissue, to obtain reliable data on the effect of some of them on the nature of bone remodeling and the magnitude of spinal deformity

Orthopaedic, psychological, social and philosophical aspects of achondroplasia patients treated with the Ilizarov method

Introduction Achondroplasia is the most common skeletal dysplasia with limb shortening that can be symptomatically be treated with the Ilizarov method developed in the 20th century. Achondroplasia patients were shown to have medical and surgical possibilities for height increase with indications being controversial, and psychological and social implications to be considered. Objective The purpose of the study was to review our own data and reported findings on possibilities, results and complications of Ilizarov treatment of achondroplasia patients. Material and methods Outcomes of 750 achondroplasia patients treated at the Kurgan Ilizarov Center between 1976 and 2017 were reviewed. The patients’age ranged from 4 to 23 years. Results Long-term outcomes were followed up in all the cases. Radiography was used to assess limb elongation at follow-ups and MRI, MSCT and US were optional. Ten-to-fifteen-year follow-ups showed persisted length gain, early osteoarthritis of the hip and knee joints due to baseline articular changes, completely restructured femur and tibia at the distraction site, normal anatomy and area of muscle cross-section, normal structure and thickness of tibial muscles. Social and psychological profile appeared to improve. We have data from the patients who underwent limb lengthening 30 years ago. Many of them are employed, have family and children. Conclusion The findings suggest that achondroplasia patients, a comparatively small group of short statured people, have good reasons to feel empowered, get social support, make parents happy and contribute to the success of the country. The Ilizarov method has turned the idea of height increase into an accomplishment for benefits of doctors and patients being an achievement of orthopaedic world to address orthopaedic, social, psychological and philosophical issues

Biochemical blood parameters in determining the elastic properties of the vascular wall in hypertensive patients with abdominal obesity

The article describes approaches that use parameters of biochemical laboratory markers as the basis for the indirect determination of the value of a functional parameter 'pulse wave velocity*, which characterizes the stiffness of the vessel wall. Using a mathematical model of an artificial neural network makes it possible to assess the degree of deviation of the resulting stiffness of the vessel wall from the standard value. An increase in this value is determined by the defeat of the vascular wall as a target organ that helps to clarify the stage of hypertension and optimize antihypertensive therapy in hypertensive patients with abdominal obesity.В статье описаны подходы, позволяющие использовать параметры биохимических лаб раторных маркеров в качестве основы для оценки величины функционального параметра «скорость распространения пульсовой волны», характеризующего жесткость сосудистой стенки. Использование математической модели искусственной нейронной сети дает возможность оценить степень отклонения полученного показателя жесткости сосудистой стенки от нормативного значения. При повышении этого значения определяется поражение сосудистой стенки как органа-мишени, что позволяет уточнить стадию артериальной гипертонии и провести оптимизацию антигипертензивной терапии у больных артериальной гипертонией с абдоминальным ожирением

Search for the lepton-flavor violating decay Bs0 →φμ±τ

A search for the lepton-flavor violating decays Bs0→φμ±τ is presented, using a sample of proton-proton collisions at center-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9 fb-1. The τ leptons are selected using decays with three charged pions. No significant excess is observed, and an upper limit on the branching fraction is determined to be B(Bs0→φμ±τ)<1.0×10-5 at 90% confidence level

Search for the rare decay of charmed baryon Λc+ into the pμ+μ- final state

A search for the nonresonant Λc+→pμ+μ- decay is performed using proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the LHCb experiment, corresponding to an integrated luminosity of 5.4 fb-1. No evidence for the decay is found in the dimuon invariant-mass regions where the expected contributions of resonances is subdominant. The upper limit on the branching fraction of the Λc+→pμ+μ- decay is determined to be 2.9(3.2)×10-8 at 90%(95%) confidence level. The branching fractions in the dimuon invariant-mass regions dominated by the η, ρ and ω resonances are also determined

Observation of the decays B(s)0→Ds1(2536)∓K±B_{(s)}^{0}\to D_{s1}(2536)^{\mp}K^{\pm}

This paper reports the observation of the decays $B_{(s)}^{0}\to D_{s1}(2536)^{\mp}K^{\pm}$ using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of $9\,\mathrm{fb}^{-1}$. The branching fractions of these decays are measured relative to the normalisation channel $B^{0}\to \overline{D}^{0}K^{+}K^{-}$. The $D_{s1}(2536)^{-}$ meson is reconstructed in the $\overline{D}^{*}(2007)^{0}K^{-}$ decay channel and the products of branching fractions are measured to be $$\mathcal{B}(B_{s}^{0}\to D_{s1}(2536)^{\mp}K^{\pm})\times\mathcal{B}(D_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-})=(2.49\pm0.11\pm0.12\pm0.25\pm0.06)\times 10^{-5},$$ $$\mathcal{B}(B^{0}\to D_{s1}(2536)^{\mp}K^{\pm})\times\mathcal{B}(D_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-}) = (0.510\pm0.021\pm0.036\pm0.050)\times 10^{-5}.$$ The first uncertainty is statistical, the second systematic, and the third arises from the uncertainty of the branching fraction of the $B^{0}\to \overline{D}^{0}K^{+}K^{-}$ normalisation channel. The last uncertainty in the $B_{s}^{0}$ result is due to the limited knowledge of the fragmentation fraction ratio, $f_{s}/f_{d}$. The significance for the $B_{s}^{0}$ and $B^{0}$ signals is larger than $10\,\sigma$. The ratio of the helicity amplitudes which governs the angular distribution of the $D_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-}$ decay is determined from the data. The ratio of the $S$- and $D$-wave amplitudes is found to be $1.11\pm0.15\pm 0.06$ and its phase $0.70\pm0.09\pm 0.04$ rad, where the first uncertainty is statistical and the second systematic.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-014.html (LHCb public pages

Measurement of the mass difference and relative production rate of the Ωb−\Omega^-_b and Ξb−\Xi^-_b baryons

The mass difference between the $\Omega^-_b$ and $\Xi^-_b$ baryons is measured using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of $9 \, \text{fb}^{-1}$, and is found to be \begin{equation} m(\Omega^-_b)- m(\Xi^-_b) = 248.54 \pm 0.51 \text{(stat)} \pm 0.38 \text{(syst)} \, \text{MeV}/c^2. \end{equation} The mass of the $\Omega^-_b$ baryon is measured to be \begin{equation} m(\Omega^-_b)= 6045.9 \pm 0.5 \text{(stat)} \pm 0.6 \text{(syst)} \, \text{MeV}/c^2. \end{equation} This is the most precise determination of the $\Omega^-_b$ mass to date. In addition, the production rate of $\Omega^-_b$ baryons relative to that of $\Xi^-_b$ baryons is measured for the first time in $pp$ collisions, using an LHCb dataset collected at a center-of-mass energy of $13 \, \text{TeV}$ and corresponding to an integrated luminosity of $6\,\text{fb}^{-1}$. Reconstructing beauty baryons in the kinematic region $2 < \eta < 6$ and $p_T < 20\,\text{GeV}/c$ with their decays to a $J/\psi$ meson and a hyperon, the ratio \begin{equation} \frac{f_{\Omega^-_b}}{f_{\Xi^-_b}}\times\frac{\mathcal{B}(\Omega^-_b \to J/\psi \Omega^-)}{\mathcal{B}(\Xi^-_b \to J/\psi \Xi^-)} = 0.120 \pm 0.008 \text{(stat)} \pm 0.008 \text{(syst)}, \end{equation} is obtained, where $f_{\Omega^-_b}$ and $f_{\Xi^-_b}$ are the fragmentation fractions of $b$ quarks into $\Omega^-_b$ and $\Xi^-_b$ baryons, respectively, and $\mathcal{B}$ represents the branching fractions of their respective decays.Comment: 23 pages, 3 figures. All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-053.html (LHCb public pages

Probing the nature of the χc1(3872)\chi_{c1}(3872) state using radiative decays

The radiative decays $\chi_{c1}(3872)\rightarrow\psi(2S)\gamma$ and $\chi_{c1}(3872)\rightarrow J/\psi\gamma$ are used to probe the~nature of the~$\chi_{c1}(3872)$ state using proton-proton collision data collected with the LHCb detector, corresponding to an~integrated luminosity of~9fb$^{-1}$. Using the~$B^+\rightarrow \chi_{c1}(3872)K^+$decay, the $\chi_{c1}(3872)\rightarrow \psi(2S)\gamma$ process is observed for the first time and the ratio of its partial width to that of the $\chi_{c1}(3872)\rightarrow J/\psi\gamma$ decay is measured to be $$\frac{\Gamma_{\chi_{c1}(3872)\rightarrow \psi(2S)\gamma}} {\Gamma_{\chi_{c1}(3872)\rightarrow J/\psi\gamma}} = 1.67 \pm 0.21 \pm 0.12 \pm0.04 ,$$ where the first uncertainty is statistical, the second systematic and the third is due to the uncertainties on the branching fractions of the $\psi(2S)$ and $J/\psi$ mesons. The measured ratio makes the interpretation of the $\chi_{c1}(3872)$ state as a~pure $D^0\bar{D}^{*0}+\bar{D}^0D^{*0}$ molecule questionable and strongly indicates a sizeable compact charmonium or tetraquark component within the $\chi_{c1}(3872)$ state.Comment: 31 pages, 2 figures. All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2024-015.html (LHCb public pages