Rays Of Sunlight Research Articles

Efficiency enhancement of solar cell using mirror concentrator

This research is done to find out a method by which the efficiency of a solar cell can be increased by using mirror concentrator to get a higher power and optimum efficiency. At first the sun lights are incident on the mirror concentrator made of plane glass and then the reflected rays are incident to the solar cell. Flat mirror concentrator (FMC) has been used to increase the incident irradiance on solar panel system by concentrating the sun light ray on it and then to improve the cell performance. A comparison is made for the same PV solar panel systems using single and triple flat mirror concentrator. It is a beneficial and important theory of solar power plant sector. It can be used in household and any kind of industrial area. The FMC consists of two flat mirrors made of glass, with dimensions (170cm × 80cm) enclosed by aluminum frame and inclined to an angle 55° with a solar panel (160cm × 120cm) tilted at 45° from the horizon. The results indicated that when the concentrator is used with the solar panel the efficiency increased by a factor of 4.52% to 11.34%. So, the increase in efficiency of the solar cell is 6.82%.

Metal oxide-dispersed PDMS nanocomposite films with enhanced heat-shielding ability and optical transparency

Coatings that transmit visible light and shield near-infrared (NIR) rays of sunlight have potential applications in smart windows, thermal camouflage, and heat shielding encapsulations. Here, we report metal oxide-dispersed polymer nanocomposites as potential coating materials that possess a combination of NIR reflection and visible light transmission. Film coatings (∼600 μm) comprising nanocrystalline zinc oxide (ZnO), titanium dioxide (TiO2), and cupric oxide (CuO) in the range of 0–2 wt% in polydimethylsiloxane (PDMS) matrix are fabricated. At optimal compositions, these coatings provided up to 52 % reduction in the interior air temperature, measured at distances ∼3 cm beneath the surface, while, at the same time, retaining up to 70 % of visible light transparency. The NIR reflection may be attributed to a combination of the band gap of the pigment material and the difference between the refractive indices of the pigments and the polymer matrix. We present a design map that highlights different regimes of heat-shielding and light transmission space for PDMS nanocomposite films. The performance, when compared with existing reports, suggests that films fabricated in this work outperform previously reported polymeric coatings in providing a combination of heat shielding and optical transparency.

Effects of Tinuvin 292 on ageing-resistance properties of electromagnetic transparent coating

The coating for the radar must satisfy the requirements of resistance to severe weather conditions while allowing electromagnetic waves to transfer almost completely. UV protection agents are added during the coating manufacturing process to limit the effects of ultraviolet rays in sunlight, improve colour fastness, and ensure the mechanical properties of the coating. In this paper, the author presents the results of a study to evaluate the effectiveness of the amine-based UV protection agent Tinuvin 292 under test conditions of colour difference ΔE (ASTM 2244), gloss loss (TCVN 2101: 2016) on samples of electromagnetic transparent coating (ETC) based on ester epoxy alkyd resin (EEA). Electromagnetic transparent coating with 2% Tinuvin 292 additive improves ageing resistance and weather resistance, ΔE = 2.15, gloss loss reached 12.1% at an angle of 60° while ensuring durability requirements mechanics, electrical properties, and electromagnetic transparency of coating film.

Parameter design of solar optical reflection lighting system array for shadowless lighting in threshold zone of short freeway tunnel

A solar optical reflection (SOR) lighting system has been developed to illuminate the threshold zone of short freeway tunnel in the premise of zero energy consumption. To improve the limited illumination performance of SOR lighting system due to the obstruction of moving vehicles on reflected sunlight rays, this study develops a fast and simple parameter design method for shadowless lighting based on an array of multiple SOR lighting systems that makes reflected sunlight emit to the threshold zone from different angles. The effectiveness of shadowless lighting is verified by the application on a two-lane freeway of Shaanxi Province, China. Results show that the shadowless lighting can significantly improve the illuminance in threshold zone, and the improvement rate is higher for the area farther from the tunnel entrance inside the tunnel. In order to achieve shadowless lighting avoid both the vehicle and inter-system blocking on reflected sunlight, the systems should be installed roadside in a staggered array that: 1) their heights descend and lateral distances from the curb shrink in turn from near to far from the tunnel entrance, with as small vertical and horizontal deflection angles of the reflectors as possible, or 2) their heights remain identical with a reduction in the vertical deflection angles of the reflectors from near to far from the tunnel entrance.

What UV is what you get: skin injury by ultraviolet (UV) light results in renal cell loss and damage in the presence of a CD177high neutrophil population.

Abstract Immune-mediated communication between organs has been implicated in the pathogenesis of many inflammatory and autoimmune diseases. We previously showed that skin injury by UV light triggers neutrophil migration to the kidney, stimulating expression of renal injury genes. This skin-kidney axis is highly relevant to lupus patients, for whom skin exposure to UV sunlight rays can lead to kidney disease flares. Here, we applied 10X single-cell RNA-seq on saline-perfused digested kidneys and Ly6G-enriched neutrophils of B6 mice, prior to and 2 days after a single dose of UV, to define renal cell subsets damaged by skin exposure to UV and how neutrophils mediate the injury. Dimensional reduction analysis revealed 14 kidney cell types and showed that exposure to UV led to the loss of podocytes and distal tubular cells (DTCs) and an expansion in endothelial and stromal cells. Differential gene expression analysis showed that podocytes and DTCs in UV-exposed mice upregulated genes associated with renal injury, including type I interferon genes, and downregulated genes important for cellular integrity and function. Neutrophil scRNA-seq revealed a unique activated CD177 highneutrophil population in the kidneys of UV exposed mice, defined as the endpoint of the psuedotime trajectory by diffusion mapping. Ligand-receptor pair analyses showed skin injury by UV altered neutrophil interactions with renal structural cells, with expanded binding to stromal cells. While the CD177 highneutrophil cluster was dominant in the kidney, it was also found in the lung, but not in the skin and blood. These studies introduce a novel model by which CD177 highneutrophils may mediate podocyte, DTC, and stromal kidney injury secondary to sterile skin inflammation. Supported by grants from NIH (1R21AR079661 – 01, 5P20GM130454-02), The Department of Defense (W81XWH2110889), and Dartmouth Health Start Up Funds.

Pyruvate and lactate based hydrogel film inhibits UV radiation-induced skin inflammation and oxidative stress

Solar skin damage is one of the most common diseases among outdoor workers. An important cause for the damage is the ultraviolet and infrared rays in sunlight, which are absorbed by the skin in large amounts, leading to severe skin inflammation and oxidative stress. Therefore, physical prevention by shielding the light from harmful wavelengths can be an effective method of skin protection from radiation. However, for existing skin lesions, prompt treatment is essential to avoid the aggravation of the injury and promote repair. Therefore, to improve the therapeutic effect on sun-damaged skin, we attempted to design a system with a dual purpose of eliminating toxic free radicals and modulating tissue inflammatory response. Here, we designed and synthesized a poly-acryloyl lysine (P-Ac-Lys) and polyvinyl alcohol-dihydroxyphenylalanine (PVA-DOPA) composite hydrogel (PAL@PVA-DOPA Hydrogel) loaded with lactate and pyruvate, that exhibites a good free radical scavenging activity and an excellent ability to modulate the inflammatory response. Experimental results showe that this hydrogel film could effectively reduce the UV-induced skin inflammation response, alleviate pathological damage and promote the recovery of the damaged skin.

Protective effects of Lactobacillus reuteri SJ-47 strain exopolysaccharides on human skin fibroblasts damaged by UVA radiation

Ultraviolet rays in sunlight can cause skin damage and premature aging. This study demonstrates that Lactobacillus reuteri SJ-47 strain exopolysaccharides (EPS) protect human skin fibroblasts (HSF) under UVA radiation. During the course of the experiments, we investigate the oxidative stress protection and antiaging effects of exopolysaccharides on HSF at the biochemical, cellular, and molecular levels. The results show that EPS can increase the antioxidant capacity of cells, decrease the amount of reactive-oxygen species (ROS) and malondialdehyde (MDA), while improve the expression of antioxidant enzymes. At the same time, EPS can increase collagen content, which can effectively regulate the expression of genes in the senescence and apoptosis pathways, and delay skin photoaging caused by UVA irradiation.Graphical

On the Value of Doubt

On the Value of Doubt

Geographical Indication (GI) as a means of craft tourism: a case of muga silk in Assam, India

Geographical Indications (GI) is one of the tools of Intellectual Property Rights (IPR) that protects name of a good as originating in the territory of a WTO member country, a region or locality in that territory, where a given quality, reputation or other characteristics of the good is essentially attributable to its geographical origin. Muga Silk has been and continues to be an integral part of Assamese life and tradition. Assam is literally a ‘Silk country’ and silk culture is deep-rooted in the rural life and culture of Assamese people where Muga silk (Antheraea assamensis) is grown. There are 100 per cent of India’s Muga silk production is originated in Assam and hence Assam silk occupies a unique position in the sericulture map of the world. Considering the ecological conditions, food plant distribution, presence of eco-types and species of diverse nature in co-existence, it is speculated that this region is home of origin of Muga (Antheraea assamensis). Muga cloth has 85.8 per cent absorption capacity of ultra-violet ray of sunlight. Muga, the unique golden-yellow silk of Assam was granted the Geographical Indication (GI) registration in 2007. The present research will be highlighted the geo-environmental condition, craft tourism prospect of Muga silk as well as its contribution on livelihood generation in the Brahmaputra valley of Assam. This paper tries to emphasize the possibility of craft tourism in Muga rearing areas of Assam, so that the host community might earn their livelihood from tourism activity.

Water Filter Operating on Solar System

In this paper, we highlight the effects of contaminated water on humans as well as the crisis of water supply and distribution of potable water in many areas of developing countries. While water is the most important substance on earth and a primary human need, contaminated water can cause and spread diseases. It is, therefore, necessary to ensure that water is purified and decontaminated for daily use at a low cost. The design of solar-powered water purification systems is thus regarded as an important means of producing clean water. Solar energy poses no polluting effect and has become a dependable energy source for usage. The design of a solar-powered water purification system is based totally on the thermal method by using the thermal heating system principle which converts sunlight rays into heat. The most vital aspect is the absorption of heat to induce evaporation of water. Research shows that flat plate collectors produce heat at relatively low temperatures (27°C to 60°C) and are commonly used to heat liquids. A solar-powered water purification system consists of a solar collector that absorbs sunlight to ensure vaporisation, which is the first stage of purifying and a filter that removes contaminants. Four different concepts have been developed. A detailed description of the components and the operation of the systems constitute the main contribution of this paper.

Triggering receptor expressed on myeloid cells (Trem)-1 plays important roles in UVB induced immune suppression and cutaneous carcinogenesis

Abstract American Cancer Society acknowledges that most skin cancers result from exposure to ultraviolet (UV) rays in sunlight. UVB radiation induces mutant cells as well as immune suppression. Tumors only occur when mutant cells are in an immune suppressive environment. The mechanisms for UVB induced immune suppression are yet to be fully elucidated. The goal of this work is to explore new mechanisms for UVB induced immune suppression and skin carcinogenesis by using advanced technology. Analysis of UVB exposed mouse (Nanostring) and human (RNAseq) skin shows that triggering receptor expressed on myeloid cells (TREM)-1 signal pathway is the top canonic pathway increased by UVB. TREM-1 has roles in inflammatory diseases and cancers. However, its role in UVB induced immune suppression and skin cancers is not understood. We have found by using multi-color flow cytometry that UVB induces TREM-1 expression in a subset of conventional dendritic cell type 2 (cDC2) in the draining lymph nodes (LN). TREM-1+ cDC2 cells are barely detected in normal LN and express a high level of the co-inhibitory molecule PD-L1. In functional assays, treatment of mice with a specific TREM-1 blocking peptide LP-17 significantly diminishes UVB-induced suppression of contact hypersensitivity responses that are mediated by T cells. Further, mice treated with this peptide show decreased incidence of photocarcinogenesis and reduced number of tumors. In summary, our findings demonstrate that UVB induces the development of a novel TREM-1+ cDC2 cell subset and that TREM-1 has an important role in UVB induced immune suppression and skin carcinogenesis. Importantly, our study implies new strategies for targeting TREM-1 in the prevention and treatment of UVB induced skin cancers. Supported by grants from NIH (R01AR072213 and R01AI154842)

Patches of altocumulus and altocumulus lenticularis catch the last rays of sunlight

WeatherVolume 77, Issue 4 p. E2-E2 Inside Cover Photograph Patches of altocumulus and altocumulus lenticularis catch the last rays of sunlight First published: 28 March 2022 https://doi.org/10.1002/wea.4189Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume77, Issue4April 2022Pages E2-E2 RelatedInformation

Management of basal cell carcinoma: our experience at tertiary care institute

Background: Basal cell carcinoma (BCC) is a slow growing, locally invasive and most common skin cancer. Its etiology is mostly linked to exposure to U.V. rays in sunlight. Diagnosis is mostly clinical and wide local excision is main treatment modality.Methods: The study was conducted on 50 cases of BCC diagnosed at Sri Guru Ramdas University of Health Sciences during a study period extending from January 2013 to January 2021. In the present study various variables associated with BCC i.e. age, gender, size, site, and histopathology were studies.Results: The present study was conducted on 50 patients of BCC. Total number of males was 32 (64%) and there were 18 (36%) females. Mean age of patients presented with BCC was 65 years and SD=14.054. It was observed that most common site of lesion was infra orbital region 12 (24%). Size of lesion varied from 1 to 3 cm and wide local excision with flap was most commonly performed procedure at our Institute. Nodular sclerosing was observed to be the most common histopathological type accounted for 35 (70%) of total cases.Conclusions: BCC is a common surface malignancy amenable to early detection and potential cure. Infra orbital region is most common site and nodular sclerosing is most common histopathological type. Wide local excision remains the heart of treatment.

Power Generation Variation Analysis Of Solar Panels Coated With TiO2

Solar energy, which is an inexhaustible, clean and easily accessible energy source, can be converted into electrical energy with the help of photovoltaic (PV) panels. Environmental factors such as dust and dirt cause pollution of PV panels and decrease the efficiency of energy conversion. One of the methods used to reduce the negative effect of dirt on panel efficiency is to coat the surface of the panels with photocatalytic materials. Oxygen and nanoparticles are formed on photocatalytic surfaces with the help of ultraviolet rays in sunlight. These particles form a chemical reaction between the coating and the surface, breaking down and destroying the dirt on the surface. In this study, the effect of titanium dioxide (TiO2) as a photocatalytic material on the efficiency of solar panels was investigated. Experimental studies were carried out in Bingöl city using two 285 W polycrystalline solar panels. One of the panel surfaces is coated with TiO2and no treatment has been applied to the surface of the other panel. When the measured data were analyzed, it was seen that while the powers of the two panels were almost the same at the beginning, with the contamination of the panels, the power obtained from theTiO2coated panel was up to 19% higher. In addition, it was observed that the excess power produced as a result of cleaning the PV panels after rainy days decreased again.

Comparative investigation of toxicity induced by UV-A and UV-C radiation using Allium test.

Organisms are increasingly exposed to ultraviolet (UV) rays of sunlight, due to the thinning of the ozone layer and its widespread use in sterilization processes, especially against the SARS-CoV-2 virus. The present study was conducted with the purpose of evaluating the damages of UV-A and UV-C radiations in Allium cepa L. roots. The effects of two different types of UV on some physiological, biochemical, cytogenotoxic, and anatomical parameters were investigated in a multifaceted study. Three groups were formed from Allium bulbs, one of which was the control group. One of the other groups was exposed to 254 nm (UV-C) and the other to 365 nm (UV-A) UV. Growth retardation effect of UV was investigated with respect to germination percentage, total weight gain, and root elongation, while cytogenotoxicity arisen from UV exposure was analyzed using mitotic index (MI) and chromosomal aberration (CA) and micronucleus (MN) frequency. Oxidative stress due to UV application was investigated based on the accumulation of malondialdehyde (MDA) and the total activities of superoxide dismutase (SOD) and catalase (CAT) enzymes. Also, anatomical changes induced by UV-A and UV-C were analyzed in root meristematic cells. UV treatments caused significant reductions in growth-related parameters. Both UV treatments caused a significant increase in MDA levels and induction of SOD and CAT enzymes in root meristematic cells. A decrease in MI and an increase in the frequency of MN and CAs were observed in root tip cells, indicating the cytogenotoxic effect of UV application. Anatomical damages such as epidermis cell damage, cortex cell damage, necrotic zones, giant cell nucleus, and indistinct transmission tissue occurred in cells exposed to UV. All of the physiological, biochemical, cytogenetic, and anatomical damages observed in this study were more severe in cells treated with UV-C compared to UV-A. This study suggested that UV exposure triggered growth inhibition, cytogenotoxicity, oxidative stress, and meristematic cell damages in A. cepa roots depending on the wavelength.

Dual Fresnel lens and segmented mirrors based efficient solar concentration system without tracking sun for solar thermal energy generation

We propose and experimentally demonstrate a combination of two large Fresnel lenses and six segmented mirrors for concentrating sunlight efficiently within a common area throughout the day without mechanical tracking the sun. The proposed system was used for efficient solar thermal power generation, i.e., efficient heating of water. The angular position of two lenses is designed and mounted in such a way that the lenses are in direct line-of-sight with the sun for efficient sunlight collection during early morning, mid-day and for evening hours. Further, the height gap between Fresnel lenses and receiver unit is sufficient enough such that there is no shadow effect on the receiver unit hence the receiver unit is also exposed to direct sunlight rays throughout the day. Due to concentration of sunlight throughout the day the efficiency of solar thermal system is significantly enhanced. This is due to the fact that with the help of the proposed system, apart from concentrated sunlight made incident on to the solar thermal receiver it is also exposed to direct sunlight. The thermal receiver unit is placed in the common area and fluid is heated very fast. The design of system using ray optics in ZEMAX and experimental study of the direct and collected incident sunlight radiations using the proposed concentrating system on the receiver unit is analyzed. The thermal performance of the proposed system is compared with combination of single large Fresnel lens and segmented mirrors. The instantaneous thermal efficiency of the proposed system is around 20% or more in comparison to single lens concentrating system. The result shows that this type of system is highly efficient, and very much useful for countries where sunlight is available in plenty. Therefore, the proposed system is very much helpful for sustainable development of country.

Large Number System from Vedas and Vedic Literature

Hinduism is undoubtedly the oldest religion of the world and though there are disagreement over the period amongst some historian but it was during 1900 to 1500 BC when Hindu religion came into existence. The foremost religious text of Hindu is Vedas and the origin of the Vedas can be traced back as far as 1500 BCE, when a large group of Aryans crossed the Hindu Kush Mountains and came to Indian subcontinent. The Vedas are full of knowledge.The Vedas have guided the Indian civilization for thousands of years and the Four Vedas are the pillar of Hinduism. The very word Veda has a derivational meaning – the fountainhead and illimitable storehouse of all knowledge. This article will only focus on the mathematical content available in Vedas, Puranas, Ramayana and Mahabharata. In Rig Veda and Atharva Veda, there are several instance where numbers in the power of tens, even numbers, odd numbers, multiples of four, value of pi, mathematical operation such as addition, subtraction, multiplication and division have been discussed not in the way we use in our courses but the presence of larger number even up to 1060 is evident. The speed of light, about seven colourful rays of sunlight all these are enough to make a belief that Vedas have put a strong foundation of number system and decimal system. Not even that, even geometrical knowledge found in Sulbha sutra as par excellence and many of them have origin prior to Greek mathematician to whom we owe everything.

Vitamin D Status and Seasonal Variation: A Retrospective Single Institution Database Study of Patients Pursuing Metabolic/Bariatric Surgery

•Marked seasonal variation was present in persons presenting for bariatric surgery.•Tailored supplementation in spring/winter should be considered to prevent vitamin D deficiency.•Pre and post-operative supplementation may be dependent on surgical type. BackgroundObesity is associated with suboptimal levels in vitamin D, a nutrient important for bone health and immune function. Seasonal variation in vitamin D may exacerbate this deficiency in persons with obesity, as exposure to ultraviolet B rays in sunlight is necessary for the conversion of vitamin D to its active form in the body. The aim of this study was to determine the relationship between season and vitamin D levels in persons with obesity pursuing bariatric surgery.Materials and MethodsThis retrospective cohort study from a single academic medical center investigated adult patients undergoing either primary sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) over a 20-year period. Demographics and serum 25-hydroxyvitamin D3 levels were collected from the first presenting visit to the bariatrics center. Continuous vitamin D3 levels were compared across seasons using a one-way Analysis of Variance (ANOVA). Vitamin D3 categories were examined across seasons using a Chi square test of independence.Results1,256 persons pursuing bariatric surgery (SG: N=697, RYGB: N=559) met the inclusion criteria. Baseline vitamin D values were available in 1,071 of the eligible patients. Overall, serum 25-hydroxyvitamin D3 levels showed a significant variation across the seasons of the year (P<0.001), with highest levels during summer (33.52±12.70 ng/mL) and lowest levels during spring (29.72±12.34 ng/mL) and winter (29.90±14.80 ng/mL).ConclusionsThis study demonstrates marked seasonal variation in serum 25-hydroxyvitamin D3 in patients with obesity presenting for bariatric surgery. These results emphasize the importance of utilizing tailored supplementation during the spring and winter months to prevent potential deficiency. Obesity is associated with suboptimal levels in vitamin D, a nutrient important for bone health and immune function. Seasonal variation in vitamin D may exacerbate this deficiency in persons with obesity, as exposure to ultraviolet B rays in sunlight is necessary for the conversion of vitamin D to its active form in the body. The aim of this study was to determine the relationship between season and vitamin D levels in persons with obesity pursuing bariatric surgery. This retrospective cohort study from a single academic medical center investigated adult patients undergoing either primary sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) over a 20-year period. Demographics and serum 25-hydroxyvitamin D3 levels were collected from the first presenting visit to the bariatrics center. Continuous vitamin D3 levels were compared across seasons using a one-way Analysis of Variance (ANOVA). Vitamin D3 categories were examined across seasons using a Chi square test of independence. 1,256 persons pursuing bariatric surgery (SG: N=697, RYGB: N=559) met the inclusion criteria. Baseline vitamin D values were available in 1,071 of the eligible patients. Overall, serum 25-hydroxyvitamin D3 levels showed a significant variation across the seasons of the year (P<0.001), with highest levels during summer (33.52±12.70 ng/mL) and lowest levels during spring (29.72±12.34 ng/mL) and winter (29.90±14.80 ng/mL). This study demonstrates marked seasonal variation in serum 25-hydroxyvitamin D3 in patients with obesity presenting for bariatric surgery. These results emphasize the importance of utilizing tailored supplementation during the spring and winter months to prevent potential deficiency.

IoT Enabled Low Cost Distributed Angle Measurement Fault Detection System for LFR Plants

The advances in renewable solar energy generation have led to the development of Linear Fresnel Reflector (LFR) technology, in which solar energy is focused by means of a set of longitudinal mirrors onto a tubular receiver. The efficiency in the energy generation process is mainly given by the relation between the angle of incidence of incoming sunlight rays and the fixed location of the elevated tubular receiver. In order to maximize efficiency, the tilt angles for each one of the longitudinal mirrors should vary as a function of solar position tracking. The angular variation process is generally based on the use of encoders implementing a closed-loop feedback system to provide information to the controller in relation with actual mirror angular position. An alternative that has recently emerged is the use of inclinometers in order to obtain angular information, providing a cost-effective solution in order to employ angular information for mirror position control. In this work, a low cost monitoring system for LFR plants is presented, based on the use of a distributed configuration to obtain information related to mirror inclination angles. The proposed system is based on the use of accelerometers coupled to low cost wireless transceivers, enabling distributed real time data collection. The system allows fault or damage detection at all monitored mirror sections, avoiding long periods of efficiency loss of the LFR plant. The configuration and location of the wireless sensor nodes has been analyzed by means of deterministic 3D Ray Launching channel modeling, in order to optimize coverage/capacity relations within the scenario under test. The proposed system has been implemented enabling remote LFR facility monitoring by means of cloud-based infrastructure. In addition, the system is highly scalable, allowing the inclusion of other interesting applications such as intruder detection for security.

Being in the shadow of the unknown — Swedish women’s lived experiences of pregnancy during the COVID-19 pandemic, a phenomenological study

BackgroundThe COVID-19 pandemic has had a profound effect on the emotional well-being of expecting mothers. Sweden’s unique strategy for managing COVID-19 involved no national lockdown. Emphasis was instead placed on limiting crowding and asking citizens to practice social distancing measures. AimTo gain a deeper understanding of how women not infected by SARS-CoV-2 experienced pregnancy during the COVID-19 pandemic in Sweden. MethodsThis was a qualitative study with a reflective lifeworld approach. Fourteen women that had not contracted COVID-19 and who were pregnant during the first and second wave of the pandemic were interviewed. Data were analysed with a phenomenological reflective lifeworld approach. FindingsThe essence of the women’s experiences of being pregnant during the COVID-19 pandemic was best described as being in the shadow of the unknown, where the COVID-19 pandemic could at times totally overshadow the experience of being pregnant, while at other times, rays of sunlight pierced through the clouds. The experience was characterised by having to deal with the uncertainties caused by the pandemic and feelings of being in an information echo. Women felt socially isolated and had to face maternal check-ups without the support of their partners. There was, however, a strong trust in maternal health-care services despite the lack of information available. ConclusionBeing in the shadow of the unknown represents the uncertainties posed by the COVID-19 pandemic on the experience of pregnancy. Sufficient information, a companion of choice and screening for emotional well-being are important factors in maternity care during pandemics.