Year XXXIV, Issue 3, 2025<<Archive>>

Olympiаds, Compеtitions in Nаturаl Sciеncеs

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CHEMISTRY FESTIVAL 2025

“Chemistry Festival” is a student competition designed for students from 5th to 12th grade. The goal of the competition is to promote chemistry among young people and provide a platform for students interested in the natural sciences to showcase their talents....

chemistry education; informal education; competition

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THE FATAL 13

Aluminum is a part of our lives, whether we realize it or not. Every day, we use objects that contain this metal. But behind its everyday use lies a long and fascinating history filled with scientific discovery, curiosity, and perseverance. This is what inspir...

metal; aluminum; experiment; recycling

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THE CHEMISTRY OF BANKNOTES AND COINS – PROGRESS OF SCIENCE

The paper examines the role of chemistry in the production and protection of banknotes and coins – key elements of economic life. It is explained that banknotes are made of special paper containing cotton or linen fibers, and in more modern cases – from a poly...

chemistry; banknotes; coins; durability; falsification

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CHEMISTRY OF BANKNOTES AND COINS FROM THE TIME OF OUR GREAT-GRANDPARENTS TO THE PRESENT DAY

The paper examines the importance of chemistry in the production and protection of banknotes and coins from antiquity to the present day. It describes the historical development of money – from natural materials to gold and silver coins, and later paper and po...

chemistry, banknotes, coins, gold, polymer

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CHEMISTRY OF MEAD

The paper examines the chemical, biochemical, microbiological and fermentation processes involved in the production of an ancient, long-forgotten drink that is becoming increasingly popular today - mead. Low-alcohol craft mead (13.5% alcohol) was prepared at h...

mead; making homemade mead; branding

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CHEMISTRY OF BANKNOTES AND COINS

The goal of every person is to realize themselves through the acquisition of knowledge and skills, in this sense, money is only a means to achieve goals. That is why Peter Thiel is cited at the beginning of the paper. The topic of the chemistry of banknotes an...

chemistry; money; banknotes; protection; technology

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ALUMINUM – THE ‚LUCKY‘ 13TH ELEMENT

The essay focuses on aluminum, calling it the “lucky” 13th element, because, from its discovery to the present day, it has been linked to technological progress. Its chemical and physical properties make it important and indispensable. It is no coincidence tha...

aluminum; astronautics; space research

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THE METAL OF TIME

The theme of the paper is about how chemistry helped Bulgaria create its first real money, because behind each coin lies more than just metal – it carries scientific thought, political will and even a bit of national pride. The essay explains how copper, silve...

chemistry; coins; metals; copper; silver; history; Principality of Bulgaria; scientific approach

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IS FRENCH ONION SOUP SWEET?

The paper explores the chemical nature of the transformation in onion flavour during thermal processing. The aim of the study is to explain how, through chemical reactions – particularly the Maillard reaction and caramelization – onions change their pungent ta...

onion; carbohydrates; Maillard reaction; caramelization; taste; food chemistry

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ALUMINUM – THE LIGHTWEIGHT HEAVY IN AUTOMOTIVE INDUSTRY

The poster reveals the properties and uses of a very valuable metal today – aluminum. The aim is to introduce people to this incredible metal that has been used for over 200 years, but is ideal for both modern life and the future. The first section provides in...

aluminum; properties; automotive industry; green metal

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MONEY – HISTORY AND NECESSITY

Money has accompanied human history since the dawn of civilizations – from bartering and cocoa beans to electronic cryptocurrencies. The first coins appeared in Lydia in the 7th century BC, marking the beginning of the classical payment model. With the growth...

barter; money; coins; cryptocurrencies; polymer banknotes; bitcoin

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CHEMISTRY OF PAPER BANKNOTES – US DOLLAR

With the development of modern technologies and the progress in chemistry, paper banknotes have become complex financial instruments that combine art, science and security. This is necessary to prevent counterfeiting and to ensure the authenticity of the curre...

banknotes; falsification; technology; ink; watermark

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ALUMINUM –FROM WASTE TO RESOURCE

Recycling aluminum is not just an option – it is a necessity. In a world where resources are becoming increasingly scarce and pollution is increasing, it is our responsibility to act sustainably. Our team believes that change starts with each individual‘s awar...

recycling; circular economy; natural resources conservation; clean planet

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THE METAL OF ELEGANCE: ALUMINUM IN MODERN JEWELRY

The paper examines the use of aluminum in jewelry on the occasion of the 200th anniversary of the metal’s discovery. It focuses on the physicochemical properties of aluminum – lightness, ductility, corrosion resistance, softness and aesthetic shine. It examine...

aluminum; jewelry; properties; sapphire; ruby

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THE SECRET CHEMISTRY OF SWISS BANKNOTES

Swiss banknotes use innovative and resistant pigments to achieve rich colors and protect against counterfeiting. The yellow color of the 10-franc banknote is due to arylide yellow, a non-toxic organic pigment with excellent resistance. The red 20-franc banknot...

color; sustainability; symbolism

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CHEMISTRY – DETECTIVE OR CRIMINAL?

The project explores the dual role of chemistry in the context of currency counterfeiting – both as a means of committing a crime and as a tool for its detection. Authors analyze the methods counterfeiters use to replicate the structure, inks, and security fea...

counterfeit; chemical analysis; fluorescence

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BABY SHAMPOO FROM EDIBLE INGREDIENTS: FORMULATION OF A NEW COSMETIC PRODUCT

The aim of this pedagogical practice is to develop pupils’ interest in natural sciences through participation in practical, creative, and socially significant activities. The project demonstrates how scientific knowledge in biology, chemistry and technology ca...

baby shampoo; natural cosmetics; natural ingredients; skin safety

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BULGARIA’S NAME FOR LONGEVITY

Nowadays, there is growing discussion about healthy living, which is associated not only with physical activity but also with nutrition. It is important to understand which foods have a positive impact on human health—one of the key indicators of longevity. Th...

yoghurt; fermentation; lactic acid bacteria; longevity

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CHEMISTRY OF COINS

The study examines the chemical composition and structure of ancient coins, the technologies used for their minting, and the processes of aging and corrosion. Various metals and their characteristics affecting the durability and appearance of coins are present...

coins; metals; corrosion; patina; dry cleaning; authenticity

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CHEMISTRY OF CHOCOLATE

Chocolate has an ancient history – from the cocoa beans of the Mayans and Aztecs to today’s global industry. In this study, we examined its composition, focusing on theobromine and caffeine – alkaloids with an effect on the nervous system. We conducted experim...

chocolate; chemistry; composition; influence; moderation

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THE CHEMISTRY OF MONEY

The study is related to the materials used to make modern banknotes and coins, as well as methods for protecting them from counterfeiting. Two main types of banknotes are presented – made of cotton and linen, as well as polymer banknotes made of synthetic plas...

banknotes; coins; polymer; fluorescence

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ALUMINUM IN CRYOGENICS

This paper is dedicated to the 200th anniversary of the discovery of aluminum and explores its applications in cryogenics. Aluminum is a group IIIA metal with a constant valence of 3, and it possesses properties that make it effective at extremely low temperat...

aluminum; cryogenics; low temperatures; industrial applications

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APPLICATION OF ALUMINUM IN VACCINES

In parallel with the increase in the bioavailability of aluminum, there has been a widespread increase in aluminum exposure in humans, primarily through vaccination. Aluminum salts in vaccines act as adjuvants - substances that enhance the immune response and...

aluminum adjuvants; vaccines; “depot effect”; autism; “Gulf War syndrome”

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ALUMINUM: “WINGS OF HUMANITY – FAVORITE 13”

In the year that marks the 200th anniversary of the discovery of aluminum, my project has conducted research that reveals what makes aluminum so special. From one to seven, I reveal that element No. 13 – the “winged”, “airy” one – has a long history, has incre...

discovery; physical and chemical properties; recycling; environment; industry; health

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THE CHEMISTRY IN HONEY

Honey, known as “liquid gold,” is one of the most valuable natural food products. It has been known to humans since ancient Egyptian times. Honey is the result of the labor of worker bees. They collect nectar from plants, place it in a honeycomb cell, and seal...

bee honey; worker bees; nectar; carbohydrates

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USE OF ALUMINUM IN JEWELRY. JEWELRY MADE OF ALUMINUM WIRE

The aim of this paper is to explore a rather unconventional and unexpected use of aluminum in fashion and jewelry. Fashion innovators such as Paco Rabanne, Thierry Mugler, Stella McCartney, Iris van Herpen, Gareth Pugh, and Olivier Rousteing have experimented...

aluminum; fashion; jewelry; aluminum wire; aluminum wire jewelry; entrepreneurship

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DAIRY CHEMISTRY

Food chemistry is a fundamental discipline that studies the composition and chemical reactions of food components during processing, contributing to the development of safer, higher-quality products. Cow‘s milk is rich in nutrients: containing water, proteins...

cow‘s milk; lactic acid fermentation; casein; unsaturated fats; cheese

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CHEMISTRY OF OLIVES

The main subject of the study is food chemistry, in particular – chemistry in olives. The research begins with an introduction that includes information about the olive tree, the leading producers on the global scale and its economic significance. The chemical...

olives; chemical composition; processing; olive oil

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CHEMISTRY OF SPICY

The project examines the different types of chemical compounds responsible for the sensation of spiciness: Capsaicin (in chili peppers), piperine (in black and white pepper), gingerol (in ginger), allyl isothiocyanate (in wasabi and mustard) and allicin (in on...

spicy; capsaicin; piperine; gingerol; allyl isothiocyanate; allicin

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JUJUBE – RESEARCH ON THE CONTENT OF VITAMIN C

The paper presents information about the jujube plant, including a brief overview of its physiology, its chemical composition, specific beneficial properties, and its use in both traditional medicine and cooking. To demonstrate the fruit’s beneficial propertie...

Jujube; Ascorbis acid; Iodine; orange; Vitamin C; cornstarch

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ALUMINUM – THE WONDERFUL METAL THAT SHAPED MODERN CIVILIZATION

The main goal of the project is to demonstrate why aluminum is a material of great importance, both today and in the future. It outlines the history of aluminum – from its discovery to the present—as well as its key properties and applications. The environment...

aluminum; ecology; experiment; hydrochloric acid

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CHEMISTRY OF MONEY

This paper examines the chemical aspects of money as a material object in the modern economy. It focuses on the composition and structure of Bulgarian coins and banknotes, analyzing the metals, alloys, and polymers used in their production. Physicochemical met...

coins; banknotes; alloys; corrosion; fluorescence

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THE EFFECT OF MARINADES ON MEAT

The present project explores the biochemical process of marination. Its aim is to demonstrate the importance of protein denaturation in increasing meat elasticity. Three types of meat are examined in eight different marinades, grouped into four categories: aci...

marination; marinade; denaturation; elasticity; meat color

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ANALYSIS OF NATURAL WATERS IN THE MUNICIPALITY OF SLIVEN

The quality of natural waters and their protection from pollution is crucial for the health of people and ecosystems. Water cleanliness in Sliven is particularly relevant today, due to the presence of numerous sources of pollutants in and around the city. This...

chemical analysis; experiments; water hardness; water purity

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CAN HOME TESTS RELIABLY DETERMINE THE QUALITY AND AUTHENTICITY OF HONEY?

Honey is a valuable product, known for its health benefits and unique taste. Counterfeit products are often found on the market, which may contain additives such as sugar syrup, water, and others. This study aims to compare home tests to see if they give co...

honey; quality; authenticity, laboratory analyses, home tests

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THE THIRTEENTH ELEMENT – SAVER OR SILENT DESTROYER?

This research project investigates the impact of aluminum on human health, focusing on the potential risks associated with the use of aluminum cookware and food packaging. Aluminum is a widely used metal in the food and medical industries. Despite the long-sta...

aluminum cookware; health risks; neurotoxic effects; \(\mathrm{Al}^{3+}\) ions, heat treating; acidic foods