49 research outputs found
Monitoring Of a Commercial Refrigeration CO2 System And Comparison With Simulations
The demand for natural refrigerants is growing in commercial refrigeration systems. In the recent years, carbon dioxide has increased its market share in the field of commercial refrigeration and has proven to be a viable solution for the replacement of hydrofluorocarbon (HFC) systems. This success is mainly due to the ongoing technological evolution of carbon dioxide refrigeration systems. In the present paper, a CO2 commercial refrigeration unit serving a supermarket located in Northern Italy is presented. The unit consists of a booster compressor rack with parallel compression, with ten compressors arranged to provide around 20 kW cooling capacity at low temperature and 90 kW cooling capacity at medium temperature. Four out of ten compressors, provided by Frascold®, are arranged in parallel. The installation, in addition to the cooling load, provides all the thermal functions in one unit: it integrates a heat exchanger for the air conditioning and the possibility of two stage heat recovery, for sanitary hot water production and for space heating. The refrigeration unit is equipped with pressure and temperature sensors, power consumption and load analysers for the compressors. A computer model has been developed to evaluate the acquired data of the system and to analyse the key parameters. The preliminary results from the monitoring of this unit are presented in this paper and used to calibrate the model of the system. Afterwards, simulations have been performed at variable operating conditions in a cold month to evaluate the performance of the unit. The results of the model have been compared to an independent set of monitoring data
Vicende climatiche e vicende umane nel Salento. Dal manoscritto di un Anonimo "Discorso dell'Anno calamitoso Mille settecento venti sette".
Energy analysis of CO2 refrigeration systems using measured values of compressor efficiency
CXCR3 and its ligant CXCL10 are expressed by inflammatory cells infiltrating lung allografts and mediate chemotaxis of T cells at sites of rejection
The attraction of T lymphocytes into the pulmonary parenchyma represents an essential step in mechanisms ultimately leading to lung allograft rejection. In this study we evaluated whether IP-10 (CXCL10), a chemokine that is induced by interferon-gamma and stimulates the directional migration of activated T cells, plays a role in regulating the trafficking of effector T cells during lung allograft rejection episodes. Immunohistochemical examination showed that areas characterized by acute cellular rejection (grades 1 to 4) and active obliterative bronchiolitis (chronic rejection, Ca) were infiltrated by T cells expressing CXCR3, i.e., the specific receptor for CXCL10. In parallel, T cells accumulating in the bronchoalveolar lavage of lung transplant recipients with rejection episodes were CXCR3+ and exhibited a strong in vitro migratory capability in response to CXCL10. In lung biopsies, CXCL10 was abundantly expressed by graft-infiltrating macrophages and occasionally by epithelial cells. Alveolar macrophages expressed and secreted definite levels of CXCL10 capable of inducing chemotaxis of the CXCR3+ T-cell line 300-19; the secretory capability of alveolar macrophages was up-regulated by preincubation with interferon-gamma. Interestingly, striking levels of CXCR3 ligands could be demonstrated in the fluid component of the bronchoalveolar lavage in individuals with rejection episodes. These data indicate the role of the CXCR3/CXCL10 interactions in the recruitment of lymphocytes at sites of lung rejection and provide a rationale for the use of agents that block the CXCR3/CXCL10 axis in the treatment of lung allograft rejection
Integrated CO2 systems for supermarkets: field measurements and assessment for alternative solutions in hot climate
Body-Size Perception among First-Generation Chinese Migrants in Italy
Body-size perception is an important factor in motivating people to lose weight. Study aim was to explore the perception of body image among first-generation Chinese migrants living in Italy. A sample of 1258 Chinese first-generation immigrants and of 285 native Italians living in Prato, Italy, underwent blood pressure measurements, blood tests (with measurement of glucose, cholesterol, and triglycerides), and anthropometric measurements. Body-size perception was investigated with Pulvers’ figure rating scale using logistic or linear multivariable regression adjusted for age, gender, BMI, education and years spent in Italy. Chinese migrants had lower BMI and discrepancy score (preferred minus current body size) than Italians (p < 0.05 for both). After a logistic regression analysis, the discrepancy score remained lower in the Chinese than in the Italian cohort independently from BMI and other confounders (OR 0.68; 95%CI 0.50 to 0.92). In the Chinese cohort, female gender, BMI and years spent in Italy were positive determinants of discrepancy score (desire to be thinner), while age showed negative impact (p < 0.05 for all). Overweight is an important risk factor for diabetes, a very prevalent condition among first-generation Chinese migrants. The present study offers useful information and suggests the need for prevention programs specifically addressed to men
The RVG system: clinical, ergonomic and radioprotection aspects
In view of the need to increase the application of ergonomic
and radioprotection principles in dentistry,
the authors explored the possibility of reducing the exposure
times of conventional radiographic examinations
by using more sensitive (F speed) films. They also
examined the scope for simplifying, through recourse
to digital systems, certain procedures used in
endodontic treatment, namely the realisation, filing
and management of radiographic images.
The Visualix HDI, Denoptix, Trophy RVG 5 Gold, Trophy-
Kodak RVG Ultimate, RVG Anthos DSX, and RVG
Schick CDR digital systems were considered. A total
of 138 examinations (74 using stiff sensors, 18 using
Denoptix system phosphorus sensors, and 46 using
conventional F speed film) were carried out. Similar
projections of the examined teeth were used in all the
examinations, both conventional and digital.
Dental clamps were applied to the examined teeth in
order to simulate digital clinical procedures. The possibility
of using rigid sensors in the presence of different
oral morphologies was evaluated. Conventional
images and projections were compared qualitatively
with digital ones.
The visual definition of the apical third of 08-10-15 Kfiles,
used in the digital examination of the root canal
length of 17 extracted teeth, was also considered.
The use of self-adhesive sensor holders and XCP-D
Two years of on-site influenza vaccination strategy in an Italian university hospital: main results and lessons learned
Although the vaccination of healthcare workers (HCWs) is considered essential for preventing influenza circulation in the hospital setting, vaccination coverage (VC) in this group remains low. Among the reasons cited by HCWs is a lack of time to attend the vaccination clinic. For the 2018/2019 influenza season, active (on-site) influenza vaccination was offered directly in 44 operative units (OUs) of the Bari Policlinico hospital (50 OUs, 3,397 HCWs). At the same time, the hospital granted the HCW access to the vaccination clinic during October and December 2018. VC achieved among HCWs of Bari Policlinico during the 2018/2019 influenza season was then analyzed, and the results compared with those of the 2017/18 season. During the 2018/19 season, VC was 20.4% (n = 798) and thus higher than the 14.2% of the 2017/18 season (+6.2%). The highest VC was among physicians (33.4%), followed by other HCWs (23.8%), auxiliary staff (8.6%), and nurses (7.2%). Overall, 284 (36.5%) HCWs were vaccinated at on-site sessions. Multivariate analysis showed that vaccination uptake was associated with male gender and with work in OU where vaccination was actively offered. On the other hand, being a nurse or auxiliary staff member and working in the surgical area were deterrents. Although VC remained unsatisfactory, active on-site vaccination proved to be an important strategy to improve vaccination compliance, increasing 44% compared to the previous season. Nonetheless, mandatory vaccination directed by public health institutions may be the only way to reach a minimum level of coverage
CXCR3/CXCL10 interactions in the development of hypersensitivity pneumonitis
Abstract Background Hypersensitivity pneumonitis (HP) is an interstitial lung disease caused by repeated inhalations of finely dispersed organic particles or low molecular weight chemicals. The disease is characterized by an alveolitis sustained by CD8(+) cytotoxic T lymphocytes, granuloma formation, and, whenever antigenic exposition continues, fibrosis. Although it is known that T-cell migration into the lungs is crucial in HP reaction, mechanisms implicated in this process remain undefined. Methods Using flow cytometry, immunohistochemistry, confocal microscopy analysis and chemotaxis assays we evaluated whether CXCL10 and its receptor CXCR3 regulate the trafficking of CD8(+) T cells in HP lung. Results Our data demonstrated that lymphocytes infiltrating lung biopsies are CD8 T cells which strongly stain for CXCR3. However, T cells accumulating in the BAL of HP were CXCR3(+)/IFNγ(+) Tc1 cells exhibiting a strong in vitro migratory capability in response to CXCL10. Alveolar macrophages expressed and secreted, in response to IFN-γ, definite levels of CXCL10 capable of inducing chemotaxis of the CXCR3(+) T-cell line. Interestingly, striking levels of CXCR3 ligands could be demonstrated in the fluid component of the BAL in individuals with HP. Conclusion These data indicate that IFN-γ mediates the recruitment of lymphocytes into the lung via production of the chemokine CXCL10, resulting in Tc1-cell alveolitis and granuloma formation.</p